LabAssay (TM) ALT (GPT)

Alanine aminotransferase (ALT) is an enzyme that catalyzes the conversion of alanine and α-ketoglutarate through amino group transfer. Previously known as glutamate pyruvate transaminase (GPT), its name was revised to conform to international nomenclature standards. ALT is involved in intracellular amino acid metabolism and gluconeogenesis in the liver, and is highly abundant in liver tissue, whereas its expression level is low in non-hepatic tissues in rats and humans. Given these characteristics, ALT is widely used as a primary marker of liver dysfunction.

LabAssay™ ALT (GPT) is a kit for measuring ALT in blood (serum, plasma). With the use of microplate, this kit provides a quick and convenient method for measuring ALT in samples.

[Note] LabAssay™ series are reagents for research purposes. They cannot be used for diagnostic purposes.

Kit Performance

Target animals	Human, Mouse, Rat, Dog, Cat
Sample	Serum, Plasma
Calibration curve range	0-405 U/L
Sample volume	7 μL
Measurement duration	Approx. 40 min
Wavelength	Primary wavelength 340 nm Reference wavelength 405 nm

Example of Calibration Curve

Principle

When a sample is mixed with Substrate-Enzyme Solution and α-KG Solution, glutamate and pyruvate are formed from L-alanine and α-ketoglutarate in a reaction catalyzed by ALT in the sample. The pyruvate thus produced is converted to lactate by lactate dehydrogenase (LD). At the same time, NADH is oxidized to NAD, and the absorbance at 340 nm decreases. Finally, the reaction is stopped using a reaction Stop Solution, and the absorbance is measured to determine the ALT activity value in the sample.

Precision of assay (within assay variation)

Reproducibility was confirmed by performing quintuplicate assays of serum and plasma (EDTA) samples of two concentrations from humans with this product.

[Result]
The CV (%) of human serum was 1.6-7.0% and human plasma (EDTA) was 3.2-5.6%, indicating good reproducibility.

Reproducibility (between assay variation)

Reproducibility was confirmed by measuring human serum and plasma (EDTA) samples at three concentrations each for four days with this product.

[Result]
The CV (%) of human serum was 0.80-2.6%, and human plasma was 1.6-3.2%, indicating good reproducibility.

Dilution linearity test

Serum and plasma (EDTA) from humans, mice, rats, dogs and cats were subjected to a 2-fold serial dilution with buffer in this kit and measured to confirm linearity (measured in duplicates).

[Result]
Good linearity was confirmed for all samples within the calibration curve range.

Spiked recovery test

Standard solutions at three concentrations were added to serum/plasma (EDTA) from humans, mice, rats, dogs and cats. Next, spike-recovery tests were conducted, with each measurement performed in duplicate.

[Result]
Good recovery rate was confirmed.

Correlation with the reagent for automated biochemical analyzers

LabAssay™ ALT (GPT) (this product) and the reagent for automated biochemical analyzers were used to measure ALT in human serum and plasma (EDTA), and the correlation was confirmed.

[Result]
A high correlation was confirmed between the measured values of LabAssay™ ALT (GPT) and the reagent for automated biochemical analyzers.