Aspartate Aminotransferase in Human Serum with Roche c502

Detection of Aspartate Aminotransferase in Human Serum with Roche c502

Test Name: In vitro test for the quantitative determination of aspartate aminotransferase in human serum and plasma on Roche/Hitachi cobas c systems.
Method Name: The catalytic activity of aspartate aminotransferase is measured through the oxidation rate of NADH. It is determined by measuring the decrease in absorbance.
Results: Technical Range: 5-700 U/L
Reportable Range: 5-559.3 U/L
Reference Ranges: Males
0-11 months: not established
1-13 years: 8-60 U/L ≥14 years: 8-48 U/L
0-11 months: not established
1-13 years: 8-50 U/L ≥14 years: 8-43 U/L
Clinical Significance: The enzyme aspartate aminotransferase (AST) is widely distributed in tissue, principally hepatic, cardiac, muscle, and kidney. Elevated serum levels are found in diseases involving these tissues. Hepatobiliary diseases, such as cirrhosis, metastatic carcinoma, and viral hepatitis also increase serum AST levels.

In patients undergoing renal dialysis or those with vitamin B6 deficiency, serum AST may be decreased.

The apparent reduction in AST may be related to decreased pyridoxal phosphate, the prosthetic group for AST, resulting in an increase in the ratio of apoenzyme to holoenzyme.

Two (2) isoenzymes of AST have been detected, cytoplasmic and mitochondrial. Only the cytoplasmic isoenzyme occurs in normal serum, while the mitochondrial, together with the cytoplasmic isoenzyme, has been detected in the serum of patients with coronary and hepatobiliary disease.

Submission Criteria: For specimen collection and preparation, only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Plasma: Li-heparin and K2-EDTA plasma
Do not use fluoride plasma

The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, therefore not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases.  When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Storage and Stability:    90 Days at -20 °C
7 days at 4-8 °C
4 days at 20-25 °C

Rejection Criteria: Rejection criteria include but are not limited to:
1. Specimens containing fibrin or clots.
2. Excessive platelet clumping
3. Leaking specimens
4. Substandard mixing or collection
5. Expired or improperly stored collection tubes.
6. Improperly filled tubes based on collection tube manufacturer’s guidelines.
7. Contaminated specimens (IV fluid, foreign particles, etc.)
8. Specimens not analyzed within the appropriate time frame.
9. Samples not shipped at appropriate temperature.
10. Samples without 2 proper identifiers or samples having identifiers that do not match the electronic or paper lab requisition.
Authorization: Diagnostic testing can only be performed with approval from an authorized provider/agency.
Turn Around Time: 1 day