Chemical Pathology


Alanine aminotransferase (ALT) is primarily an enzyme marker of hepatocellular damage, but may also be increased in muscle damage.

Sample requirements

For adults, 5 ml of blood taken into a 5mL gold top gel tube (or rust top for the Acute Unit)

5ml gold tube

For children, blood taken into a 3.5mL rust top tube

3.5ml rust top tube

For neonates, blood taken into a 0.8mL minicollect lithium heparin tube.

Sample tube: pale green cap


Send at ambient temperature to the laboratory. If unavoidable, samples can be stored refrigerated overnight

Required information

Relevant clinical details including known or possible diagnoses; medication or recent exposure to possible hepatotoxic agents; recent foreign travel or contact with viral hepatitis.

Turnaround times

The assays are run throughout the day and night. The in-lab turnaround time is normally less than 24 hours. The test can be ordered as an urgent request.

Reference ranges

Male: Less than 50 U/L

Female: Less than 35 U/L

Significantly raised ALT (> 3 x ULN) or persistently mildly raised ALT (for 3 - 6 months) should be further investigated

Further information

To learn more about ALT, visit Lab Tests Online

Page last updated: 20/04/2021