Alanine aminotransferase (ALT) is an enzyme found primarily in the liver and kidney that was originally referred to as serum glutamic pyruvic transaminase (SGPT). ALT levels are normally low in the serum but increase with liver damage and are used to screen for and monitor liver disease. The ALT test works by measuring the conversion of L-alanine and α-ketoglutarate to pyruvate and glutamate by SGPT, and then measuring the intensity of the brown colored complex formed between pyruvate and 2,4-dinitrophenyl hydrazine. Elevated ALT can indicate liver damage from viral hepatitis, toxins, drugs, tumors, or chronic liver

2.  AlanineAminotransferase (ALT) is an enzyme
found primarily in the liver and kidney. It was
originally referred to as Serum Glutamic
PyruvicTransaminase (SGPT).
 Normally, a low level of ALT exists in the
serum.
 ALT is increased with liver damage and is
used to screen or monitor liver disease.

4. Principle
 SGPT converts L-Alanine and a-Ketoglutarate to
Pyruvate and Glutamate. The Pyruvate formed reacts
with 2,4,Dinitrophenyl hydrazine to produce a
hydrazone derivative, which in an alkaline medium
produces a brown coloured complex whose intensity is
measured.

5. • L-alanine + a-Ketoglutarate SGPT Pyruvate + L-Glutamate
pH 7.4
• Pyruvate + 2,4,DNPH Alkaline 2,4,Dinitrophenyl Hydrazone
Medium (Brown Coloured Complex)

6. Procedure
 One Reagent Procedure:
 Mix and after 1min incubation, measure
the change of Optical Density per min(
OD/min) during 3 minutes.
Working Reagent 1ml
Sample 0.1ml

7.  Two Reagent Procedure:
 Mix and after 1min incubation, measure the
change of Optical Density per min ( OD/min)
during 3 minutes.
Working Reagent 1ml
Sample 0.125ml
Mix, wait 1min and add
Reagent 0.250ml

8. Calculations & Normal Range
 At 340nm with one-reagent procedure and the two-
reagent procedure: Activity (U/L) = OD/min 1746.
 The reference range for ALT is 20-60 IU/L.

9.  There are 3 basic interpreting conditions:
 High Levels of ALT.
 Moderately high levels of ALT.
 Slightly high levels of ALT.

10. 1. Liver damage (acute viral hepatitis,
toxins/drugs including acetaminophen
overdose, acute fulminant hepatitis).
2. Peak levels do not necessarily correlate with
prognosis.
3. Tumor necrosis.

11.  Chronic liver disease
 Alcohol abuse
 Cholestasis
 Heart damage (heart attack, heart failure)
 Kidney damage
 Muscle injury
 Hemolysis
 Heatstroke (level dependent on extent of tissue
damage)
 High consumption of vitamin A

12.  Fatty change in the liver
 Alcohol abuse
 Cirrhosis
 Mononucleosis
 Drugs (i.e. statins, aspirin, barbiturates, HIV
medication, herbs).

13.  Serum, Heparinized or EDTA plasma free from
hemolysis.
 Hemolysis should be avoided, since ALAT activity in
erythrocytes is 3 to 5 times higher than in normal
serum.
 ALAT activity remains stable in specimen up to 3 days
at 15-25ºC or up to 7 days at 2-8ºC.
 Although samples frozen at -20ºC can be stored
longer than 7 days, it is recommended to perform the
assay with freshly collected samples!

14.  Wave Length : 340nm
 Incubation Temp : 370 C
 Incubation Time : 1 min.
 Read Time : 3 min
 No. of Readings : 4
 Interval Time : 1 min.
 Sample Volume : 0.1 ml
 Reagent Volume : 1 ml
 Unit : U/L Factor : 1746