AST

Test Code

LAB131

Quest Code

822

CPT Codes
84450

Preferred Specimen

1 mL serum

Minimum Volume

0.5 mL

Other Acceptable Specimens

Sodium heparin (green-top) tube • Lithium heparin (green-top) tube

Transport Container

Serum separator tube (SST)

Transport Temperature

Room temperature

Specimen Stability

Serum and plasma
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 5 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolysis • Anticoagulants other than heparin

Methodology
Spectrophotometry (SP)

Setup Schedule

Daily

Report Available

1 day

Reference Range

	Male (U/L)	Female (U/L)
<1 Month	3-51	3-49
1-11 Months	3-65	3-79
1-3 Years	3-56	3-69
4-6 Years	20-39	20-39
7-19 Years	12-32	12-32
20-49 Years	10-40
20-44 Years		10-30
≥45 Years		10-35
≥50 Years	10-35

Clinical Significance

AST is widely distributed throughout the tissues with significant amounts being in the heart and liver. Lesser amounts are found in skeletal muscles, kidneys, pancreas, spleen, lungs, and brain. Injury to these tissues results in the release of the AST enzyme to general circulation. In myocardial infarction, serum AST may begin to rise within 6-8 hours after onset, peak within two days and return to normal by the fourth or fifth day post infarction. An increase in serum AST is also found with hepatitis, liver necrosis, cirrhosis, and liver metastasis.

Performing Laboratory

Quest Diagnostics-Lenexa

10101 Renner Blvd

Lenexa, KS 66219-9752

Last Updated: August 13, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.