Alternative Names: ALB; Albumin, Serum; Albumin, Plasma

Test Code: ALB

Clinical Significance: Albumin is a carbohydrate free protein, which constitutes 55 65 % of total plasma protein. It maintains plasma oncotic pressure and is also involved in the transport and storage of a wide variety of ligands and is a source of endogenous amino acids. Albumin binds and solubilizes various compounds, e.g., bilirubin, calcium, and long chain fatty acids. Furthermore, albumin is capable of binding toxic heavy metal ions as well as numerous pharmaceuticals, which is the reason why lower albumin concentrations in blood have a significant effect on pharmacokinetics.

Hyperalbuminemia is of little diagnostic significance except in the case of dehydration. Hypoalbuminemia occurs during many illnesses and is caused by several factors: compromised synthesis due either to liver disease or because of reduced protein uptake; elevated catabolism due to tissue damage (severe burns) or inflammation; malabsorption of amino acids (Crohn’s disease); proteinuria because of nephrotic syndrome; protein loss via the stool (neoplastic disease). In severe cases of hypoalbuminemia, the maximum albumin concentration of plasma is 2.5 g/dL (380 µmol/L). Due to the low osmotic pressure of the plasma, water permeates through blood capillaries into tissue (edema). The determination of albumin allows monitoring of a controlled patient dietary supplementation and serves also as an excellent test of liver function.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin or K-2 EDTA Plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 5 months
• Frozen: 4 months
• Room Temperature: 2.5 months

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens should be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 4 days All 2.8 g/dL 4.4 g/dL
< 14 years All 3.8 g/dL 5.4 g/dL
< 18 years All 3.2 g/dL 4.5 g/dL
≥ 18 years All 3.5 g/dL 5.2 g/dL

LOINC Codes: 61152-5

CPT: 82040

Test Principle: Colorimetric assay performed using a Roche Cobas c503 test platform.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Test Name: Alkaline Phosphatase

Alternative Names: ALP; Alkaline Phosphatase, total

Test Code: ALP

Clinical Significance: Alkaline phosphatase in serum consists of four structural genotypes: the liver bone kidney type, the intestinal type, the placental type, and the variant from the germ cells. It occurs in osteoblasts, hepatocytes, leukocytes, the kidneys, spleen, placenta, prostate, and the small intestine. The liver bone kidney type is particularly important. A rise in the alkaline phosphatase occurs with all forms of cholestasis, particularly with obstructive jaundice. It is also elevated in diseases of the skeletal system, such as Paget’s disease, hyperparathyroidism, rickets and osteomalacia, as well as with fractures and malignant tumors. A considerable rise in the alkaline phosphatase activity is sometimes seen in children and juveniles. It is caused by increased osteoblast activity following accelerated bone growth.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 2 months
• Ambient: 7 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens should be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 14 days All 83 U/L 248 U/L
< 1 year All 122 U/L 469 U/L
< 10 years All 142 U/L 335 U/L
< 13 years All 129 U/L 417 U/L
< 17 years Male 116 U/L 468 U/L
< 19 years Male 82 U/L 331 U/L
< 999 years Male 40 U/L 129 U/L
< 17 years Female 50 U/L 117 U/L
< 19 years Female 45 U/L 87 U/L
< 999 years Female 35 U/L 104 U/L

LOINC Codes: 6768-6

CPT: 84075

Test Principle: Colorimetric assay performed using a Roche Cobas c503 test platform.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Test Name: Alanine Aminotransferase

Alternative Names: ALT; GPT; SGPT; Transaminase, SGPT

Test Code: ALTL

Clinical Significance: The enzyme alanine aminotransferase (ALT) is present in highest concentrations in the liver, in the cytosol of the hepatocytes, although it is also found in the kidney, and, in much smaller quantities, in heart and skeletal muscle cells. ALT catalyzes the transfer of amino groups from L-alanine to α-ketoglutarate, resulting in L-glutamate and pyruvate. This is a critical process of the tricarboxylic acid cycle, in which the coenzyme pyridoxal phosphate (also known as pyridoxal-5-phosphate or active vitamin B6) is required. When liver injury occurs, ALT is released from injured liver cells and causes a significant serum elevation.

Measurement of ALT activity is therefore used for the diagnosis of hepatic diseases such as acute and chronic viral hepatitis, nonalcoholic fatty liver disease (NAFLD), alcohol-related liver disease, ischemic hepatopathy, autoimmune hepatitis, biliary injury, suspected malignant infiltration, cholestatis. Serum elevations of ALT activity are rarely observed in conditions other than parenchymal liver disease. In addition, ALT testing is recommended for monitoring chronic hepatitis and progression. Although both serum aspartate aminotransferase (AST) and ALT become elevated whenever disease progresses affect liver cell integrity, evidence suggests that ALT is a more specific marker of hepatic injury than AST. Moreover, elevations of ALT activity persist longer than elevations of AST activity. In patients with vitamin B6 deficiency (insufficient endogenous pyridoxal phosphate), serum aminotransferase activity may be decreased. The addition of pyridoxal phosphate to this assay causes an increase in aminotransferase activity (activation higher for AST than for ALT) and prevents falsely low aminotransferase test results in these samples.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium heparin plasma; K2 EDTA plasma; K3 EDTA plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated:7 days
• Frozen: 7 days
• Room Temperature: 4 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens should be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
• Male: 0 to 41 U/L
• Female: 0 to 33 U/L

LOINC Codes: 6768-6

CPT: 84460

Test Principle: Testing is performed using a Roche Cobas c503 test platform. ALT measurements performed using this device, in human serum and plasma are used as an aid in diagnosis of hepatocellular injury and in monitoring chronic liver injury. ALT catalyzes the reaction between L alanine and 2 oxoglutarate. The pyruvate formed is reduced by NADH in a reaction catalyzed by lactate dehydrogenase (LDH) to form L lactate and NAD+. The rate of the NADH oxidation is directly proportional to the catalytic ALT activity. It is determined by measuring the decrease in absorbance.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Test Name: Amylase

Alternative Names: alpha-amylase, α-amylase

Test Code: AMY

Clinical Significance: The α amylases (1,4 α D glucanohydrolases, EC 3.2.1.1) catalyze the hydrolytic degradation of polymeric carbohydrates such as amylose, amylopectin, and glycogen by cleaving 1,4 α glucosidic bonds. In polysaccharides and oligosaccharides, several glycosidic bonds are hydrolyzed simultaneously. Maltotriose, the smallest such unit, is converted into maltose and glucose, albeit very slowly. Two types of α amylases can be distinguished, the pancreatic type (P type) and the salivary type (S type). Whereas the P type can be attributed almost exclusively to the pancreas and is therefore organ specific, the S type can originate from several sites. As well as appearing in the salivary glands it can also be found in tears, sweat, human milk, amniotic fluid, the lungs, testes, and the epithelium of the fallopian tube.

Because of the sparsity of specific clinical symptoms of pancreatic diseases, α amylase determinations are of considerable importance in pancreatic diagnostics. They are mainly used in the diagnosis and monitoring of acute pancreatitis. Hyperamylasemia does not, however, only occur with acute pancreatitis or in the inflammatory phase of chronic pancreatitis, but also in renal failure (reduced glomerular filtration), tumors of the lungs or ovaries, pulmonary inflammation, diseases of the salivary gland, diabetic ketoacidosis, cerebral trauma, surgical interventions or in the case of macroamylasemia. To confirm pancreatic specificity, it is recommended that an additional pancreas specific enzyme lipase or pancreatic α amylase also be determined.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated (preferred): 30 days
• Frozen: 30 days
• Ambient: 7 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 15 days All 3 U/L 10 U/L
< 13 weeks All 2 U/L 22 U/L
< 1 year All 3 U/L 50 U/L
< 19 years All 25 U/L 101 U/L
≥ 19 years All 2 8 U/L 100 U/L

LOINC Codes: 20170

CPT: 84075

Test Principle: Enzymatic colorimetric assay acc. To IFCC. Defined oligosaccharides such as 4,6-ethylidene-(G7) p-nitrophenyl-(G1)-α-D-maltoheptaoside (ethylidene-G7PNP) are cleaved under the catalytic action of α-amylases. The G2PNP, G3PNP and G4PNP fragments so formed are completely hydrolyzed to p-nitophenol and glucose by α-glucosidase. The color intensity of the p-nitrophenol formed is directly proportional to the α-amylase activity. It is determined by measuring the increase in absorbance. Assay is performed using a Roche Cobas c503 test platform.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Alternative Names: AST; GOT; SGOT; Transaminase, SGOT

Test Code: ASTL

Clinical Significance: The enzyme AST is widely distributed in tissue, primarily in the liver, cardiac muscle, skeletal muscle, kidney, brain, and erythrocytes. AST catalyzes the transfer of amino groups from L-aspartate to α-ketoglutarate, resulting in L-glutamate and oxaloacetate. This is a critical process of the tricarboxylic acid cycle, in which the coenzyme pyridoxal phosphate (also known as pyridoxal-5-phosphate or active vitamin B6) is required. In particular, AST is vital for aerobic glycolysis. AST exists in human tissues as two distinct isoenzymes, one located in the cytoplasm (c-AST), and the other in mitochondria (m-AST), which differ in amino acid composition and immunochemical and kinetic properties. In healthy individuals, the circulating AST levels consist mainly of cytoplasmic AST, originating from cytoplasmic leakage, on the other side, mitochondrial AST activity in serum shows a marked increase in patients with extensive liver cell degeneration and necrosis. Although AST activity is important in all cells with high metabolic activity, it is more relevant for liver and muscle cells.

Primarily, AST is a marker of hepatocellular injury. Measurement of AST activity is therefore used for the diagnosis of hepatic diseases such as acute and ischemic hepatopathy, suspected malignant infiltration, and cholestasis. Although alanine aminotransferase (ALT) is considered a more specific indicator of liver disease, the concentration of AST may be a more sensitive indicator of liver injury in conditions such as alcohol-related liver disease and in some cases autoimmune hepatitis. Several international guidelines recommend AST testing for monitoring chronic hepatitis status and progression.
Non-liver causes for increases in AST include damage to cardiac or skeletal muscle cells and hemolysis. Serum elevation of AST without elevation of ALT is suggestive cardiac or muscle disease. In patients undergoing renal dialysis or those with vitamin B6 deficiency, serum AST may be decreased. AST serum levels can be affected by age, gender, alcohol consumption, body mass index, dietary and living habits, nutrition, metabolic status, and drug treatment, among other factors.
In patients with vitamin B6 deficiency (insufficient endogenous pyridoxal phosphate), serum aminotransferase activity may be decreased. The addition of pyridoxal phosphate to this assay causes an increase in aminotransferase activity (activation higher for AST than for ALT) and prevents falsely low aminotransferase test results in these samples.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium heparin plasma; K2 EDTA plasma; K3 EDTA plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated (preferred): 7 days
• Frozen: 3 months
• Ambient: 4 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation:
1. Tubes containing gel must be centrifuged within 2 hours of collection.
2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.
3. Store specimens at 2 to 8° C until they are ready to be shipped.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 1 year All 20 U/L 67 U/L
< 7 years All 21 U/L 44 U/L
< 12 years All 18 U/L 36 U/L
< 19 years Male 14 U/L 35 U/L
< 19 years Female 13 U/L 26 U/L
≥ 19 years Male 0 U/L 40 U/L
≥ 19 years Female 0 U/L 32 U/L

LOINC Codes: 30239-8

CPT: 84450

Test Principle: This assay follows the recommendations of the IFCC but was optimized for performance and stability. AST catalyzes the transfer of an amino group between L aspartate and 2 oxoglutarate to form oxaloacetate and L glutamate. The oxaloacetate then reacts with NADH, in the presence of malate dehydrogenase (MDH), to form L malate and NAD+. Pyridoxal phosphate serves as a coenzyme in the amino transfer reaction. It ensures full enzyme activation. The rate of the NADH oxidation is directly proportional to the catalytic AST activity. It is determined by measuring the decrease in absorbance. Assay performed using a Roche Cobas c503 test platform. AST measurements, performed with this device, in human serum and plasma are used as an aid in diagnosis of hepatocellular injury and in monitoring chronic liver injury.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Alternative Names: DBILI; Conjugated Bilirubin

Test Code: DBIL2

Clinical Significance: Measurement of the levels of bilirubin, an organic compound formed during the normal and abnormal destruction of red blood cells, is used in the diagnosis and treatment of liver, hemolytic, hematological, and metabolic disorders, including hepatitis and gall bladder block.

Bilirubin is an organic compound formed by the reticuloendothelial system during the normal and abnormal destruction of red blood cells. Measurements of bilirubin are used in the diagnosis of liver disease, in the detection of hemolytic anemia, and to evaluate degrees of jaundice.

Since the introduction of the diazo method for bilirubin determination by Ehrlich in 1883, several modifications have been proposed to enhance the reaction. The Evelyn-Malloy method employs methanol to catalyze the azo-coupling reaction of the indirect bilirubin, as well as to keep the azobilirubin in solution. A serious disadvantage of this method lies in the fact that protein may be precipitated by the methanol solution to yield falsely lowered results.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium heparin plasma; K2 EDTA plasma; K3 EDTA plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.
6. Protect from light.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 6 months
• Ambient: 2 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 14 days Both 0.33 mg/dL 0.71 mg/dL
< 1 year Both 0.05 mg/dL 0.30 mg/dL
< 9 years Both 0.05 mg/dL 0.20 mg/dL
< 13 years Both 0.10 mg/dL 0.29 mg/dL
≥ 13 years Male 0.11 mg/dL 0.42 mg/dL
≥ 13 years Female 0.10 mg/dL 0.39 mg/dL

LOINC Codes: 1968-7

CPT: 82248

Test Principle: Diazo method performed using a Roche Cobas c503 test platform.
Conjugated bilirubin and δ bilirubin (direct bilirubin) react directly with 3,5 Dichlorophenyl diazonium salt in acid buffer to form the red-colored azobilirubin. The color intensity of the red azo dye formed is directly proportional to the director (conjugated) bilirubin concentration and can be determined photometrically.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Alternative Names: TBILI; TSB

Test Code: TBILI

Clinical Significance: Measurement of the levels of bilirubin, an organic compound formed during the normal and abnormal destruction of red blood cells, is used in the diagnosis and treatment of liver, hemolytic, hematological, and metabolic disorders, including hepatitis and gall bladder blockage.

Bilirubin is formed in the reticuloendothelial system during the degradation of aged erythrocytes. The heme portion from hemoglobin and from other heme-containing proteins is removed, metabolized to bilirubin, and transported as a complex with serum albumin to the liver. In the liver, bilirubin is conjugated with glucuronic acid for solubilization and subsequent transport through the bile duct and elimination via the digestive tract.

Diseases or conditions which, through hemolytic processes, produce bilirubin faster than the liver can metabolize it, cause the levels of unconjugated (indirect) bilirubin to increase in the circulation. Liver immaturity and several other diseases in which the bilirubin conjugation mechanism is impaired cause similar elevations of circulating unconjugated bilirubin. Bile duct obstruction or damage to hepatocellular structure causes increases in the levels of both conjugated (direct) and unconjugated (indirect) bilirubin in the circulation.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin or K-2 EDTA Plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.
6. Protect samples from light.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 6 months
• Ambient: 24 hours

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.
Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 17 years All 0.0 mg/dL 1.0 mg/dL
≥ 17 years All 0.0 mg/dL 1.2 mg/dL

Critical Value(s):
CRITICAL LOW CRITICAL HIGH
N/A Up to 1 year old: >15.0 mg/dL

LOINC Codes: 1975-2

CPT: 82247

Test Principle: Colorimetric diazo method performed using a Roche Cobas c503 test platform. Total bilirubin, in the presence of a suitable solubilizing agent, is coupled with 3,5 dichlorophenyl diazonium in a strongly acidic medium. The color intensity of the red azo dye formed is directly proportional to the total bilirubin and can be determined photometrically.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Alternative Names: Urea

Test Code: URE

Clinical Significance: Urea is the major end product of protein nitrogen metabolism. It is synthesized by the urea cycle in the liver from ammonia which is produced by amino acid deamination. Urea is excreted mostly by the kidneys, but minimal amounts are also excreted in sweat and degraded in the intestines by bacterial action.

Determination of blood urea nitrogen is the most widely used screening test for renal function. When used in conjunction with serum creatinine determinations it can aid in the differential diagnosis of the three types of azotemia: prerenal, renal and postrenal.

Elevations in blood urea nitrogen concentration are seen in inadequate renal perfusion, shock, diminished blood volume (prerenal causes), chronic nephritis, nephrosclerosis, tubular necrosis, glomerular nephritis (renal causes) and urinary tract obstruction (postrenal causes). Transient elevations may also be seen during periods of high protein intake. Unpredictable levels occur with liver diseases.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin or K-2 EDTA Plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 12 months
• Ambient: 7 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 18 years All 5 mg/dL 18 mg/dL
< 60 years All 6 mg/dL 20 mg/dL
< 90 years All 8 mg/dL 20 mg/dL

Critical Value(s)
• The critical value for patients < 18 years old is 55 mg/dL.
• The critical value for patients ≥ 18 years old is 130 mg/dL.

LOINC Codes: 3091-6

CPT: 84520

Test Principle: Kinetic test with urease and glutamate dehydrogenase. Urea is hydrolyzed by urease to form ammonium and carbonate. In the second reaction 2oxoglutarate reacts with ammonium in the presence of glutamate dehydrogenase (GLDH) and the coenzyme NADH to produce L-glutamate. In this reaction two moles of NADH are oxidized to NAD+ for each mole of urea hydrolyzed. The rate of decrease in the NADH concentration is directly proportional to the urea concentration in the specimen and is measured photometrically. This assay is performed using a Roche Cobas c503 test platform.

Specimen Retention: 7 days
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Alternative Names: Ca; Calcium, total

Test Code: CA2

Clinical Significance: Calcium is the most abundant mineral element in the body with about 99 percent in the bones primarily as hydroxyapatite. The remaining calcium is distributed between the various tissues and the extracellular fluids where it performs a vital role for many life-sustaining processes. Among the extra skeletal functions of calcium are involvement in blood coagulation, neuromuscular conduction, excitability of skeletal and cardiac muscle, enzyme activation, and the preservation of cell membrane integrity and permeability.

Serum calcium levels and hence the body content is controlled by parathyroid hormone (PTH), calcitonin, and vitamin D. An imbalance in any of these modulators leads to alterations of the body and serum calcium levels. Increases in serum PTH or vitamin D are usually associated with hypercalcemia. Increased serum calcium levels may also be observed in multiple myeloma and other neoplastic diseases. Hypocalcemia may be observed e.g., in hypoparathyroidism, nephrosis, and pancreatitis.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged as soon as possible but not exceeding two hours of collection because prolonged with the clot may cause lower calcium values.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum or lithium-hep plasma). The serum/plasma must be aliquoted as soon as possible but not exceeding two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 3 weeks
• Frozen: 8 months
• Ambient: 7 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

AGE GENDER LOWER LIMIT UPPER LIMIT
< 10 days All 7.6 mg/dL 10.4 mg/dL
< 2 years All 9.0 mg/dL 11.0 mg/dL
< 12 years All 8.8 mg/dL 10.8 mg/dL
< 18 years All 8.4 mg/dL 10.2 mg/dL
< 60 years All 8.6 mg/dL 10.0 mg/dL
< 90 years All 8.8 mg/dL 10.2 mg/dL
≥ 90 years All 8.2 mg/dL 9.6 mg/dL

Critical Values:
AGE LOWER LIMIT UPPER LIMIT
< 18 years 6.5 mg/dL 12.7 mg/dL
≥ 18 years 7.0 mg/dL 13.0 mg/dL

LOINC Codes: 17861-6

CPT: 82330

Test Principle: Calcium ions react with 5nitro5’methyl-BAPTA (NM-BAPTA) under alkaline conditions to form a complex. This complex reacts in the second step with EDTA. The change in absorbance is directly proportional to the calcium concentration and is measured photometrically. This assay is performed using a Roche Cobas c503 test platform.

Specimen Retention: 7 days
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Test Name: Chloride

Alternative Names: Cl; Chloride, serum or plasma

Test Code: CHL

Clinical Significance: is the major extracellular anion and serves to regulate the balance of extracellular fluid distribution. Similarly to the other ions, common causes of decreased chloride include reduced dietary intake, prolonged vomiting and reduced renal reabsorption as well as some forms of acidosis and alkalosis. Increased chloride values are found in dehydration, kidney failure, some forms of acidosis, high dietary or parenteral chloride intake, and salicylate poisoning.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin Plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 30 days
• Ambient: 7 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
Up to 5 years All 100 mmol/L 107 mmol/L
Up to 11 years All 101 mmol/L 107 mmol/L
Up to 29 years Male 101 mmol/L 106 mmol/L
Up to 29 years Female 100 mmol/L 107 mmol/L
≥ 29 years All 98 mmol/L 107 mmol/L

Critical Value(s): Values < 80 mmol/L or > 120 mmol/L are critical.

LOINC Codes: 2075-0

CPT: 82435

Test Principle: Ion-selective electrode performed using a Roche Cobas c503/ISE test platforms.

Specimen Retention: 7 days
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Alternative Names: Cholesterol, total; TC

Test Code: CHOL

Clinical Significance: Cholesterol is a steroid with a secondary hydroxyl group in the C3 position. It is synthesized in many types of tissue, but particularly in the liver and intestinal wall. Approximately three quarters of cholesterol is newly synthesized, and a quarter originates from dietary intake. Cholesterol assays are used for screening for atherosclerotic risk and in the diagnosis and treatment of disorders involving elevated cholesterol levels as well as lipid and lipoprotein metabolic disorders.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin or K-2 EDTA Plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Patient Preparation: Fasting is preferred but not required.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 3 months
• Ambient: 7 days

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER EXPECTED VALUE
< 17 years All ≤ 170 mg/dL
≥ 17 years All ≤ 200 mg/dL

LOINC Codes: 2093-3

CPT: 82465

Test Principle: Enzymatic, colorimetric method performed using a Roche Cobas c503 test platform. Cholesterol esters are cleaved by the action of cholesterol esterase to yield free cholesterol and fatty acids. Cholesterol oxidase then catalyzes the oxidation of cholesterol to cholest 4 en 3 one and hydrogen peroxide. In the presence of peroxidase, the hydrogen peroxide formed effects the oxidative coupling of phenol and 4 aminophenazone to form a red quinone imine dye. The color intensity of the dye formed is directly proportional to the cholesterol concentration. It is determined by measuring the increase in absorbance.

Specimen Retention: 7 days

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Test Name: CO2

Alternative Names: Bicarb; Bicarbonate; HCO3

Test Code: CO2

Clinical Significance: Bicarbonate is the second largest fraction of the anions in plasma. Included in this fraction are the bicarbonate (HCO3-) and carbonate (CO32-) ions, as well as the carbamino compounds. At the physiological pH of blood, the concentration of carbonate is 1/1000 that of bicarbonate. The carbamino compounds are also present in such low quantities that they are generally not mentioned specifically.

The bicarbonate content of serum or plasma is a significant indicator of electrolyte dispersion and anion deficit. Together with pH determination, bicarbonate measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with acid base imbalance in the respiratory and metabolic systems.

Turnaround Time: Typically, 24 hours

Preferred Specimen Type: Serum

Alternative Specimen Type: Lithium Heparin Plasma

Specimen Handling:
1. Wait for a clot to fully form (serum samples only).
2. Centrifuge the sample at 1300 to 2000 g (3000 to 3500 RPM) for 10 to 15 minutes.
3. All samples must be centrifuged within two hours of collection.
4. Tubes containing a gel separator can be stored at the appropriate temperature until they are ready to be shipped to the laboratory.
5. If there is no gel separator present, aliquot the serum/plasma into an appropriately labeled plastic screw cap transport vial. The original tube type must be written on the label of the aliquot tube (i.e., red top serum, EDTA plasma or Lavender top). The serum/plasma must be aliquoted within two hours of collection. Store the aliquoted sample at the appropriate temperature until it is ready to be shipped to the laboratory.

Sample Volume:
• Preferred: 1 mL
• Minimum: 0.5 mL

Specimen Stability:
• Refrigerated: 7 days
• Frozen: 6 months
• Ambient: 40 hours

Rejection Criteria:
• Gross hemolysis
• Gross icterus
• Gross lipemia
• Unlabeled or improperly identifiable specimens
• Samples that have not been handled or transported to the laboratory at the proper temperature
• Samples that have exceeded the stated stability
• Wrong tube type/anticoagulant
• Uncentrifuged or improperly centrifuged samples
• QNS

Specimen Transportation: Specimens must be transported to the laboratory in insulated mailers that contain at least two ice packs.

Reference Interval(s):
AGE GENDER LOWER LIMIT UPPER LIMIT
< 14 days All 5 mmol/L 20 mmol/L
< 1 year All 10 mmol/L 24 mmol/L
< 5 years All 14 mmol/L 24 mmol/L
< 6 years All 17 mmol/L 26 mmol/L
≥ 6 years All 22 mmol/L 29 mmol/L

Critical Value(s):
AGE LOWER LIMIT UPPER LIMIT
≤ 5 years N/A 40 mmol/L
≥ 5 years 10 mmol/L 40 mmol/L

LOINC Codes:
• Serum: 1963-8
• Plasma: 1962-0

CPT: 82374

Test Principle: Bicarbonate reacts with phosphoenolpyruvate (PEP) in the presence of PEPC to produce oxaloacetate and phosphate.