CHEMISTRY REAGENT KITS----->GOT AST Kinetic
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CLINICAL SIGNIFICANCE
A high activity of AsAT (AST) is the clinical indication of myocardial infarction noticeable after few hours of onset lasting for 4-5 days. High levels are also found in cases of liver cell damage, muscular dystrophy and dermatomyositis.

PRINCIPLE
L  -  aspartate    AsAT     Oxaloacetate
       +               ------®   +
a - ketoglutarate             L-glutamate

L  -   glutamate        MDH      L-malate
         +    --------® +
        NADH                   NAD

The catalytic activity of AsAT is measured by the rate of NADH dissociated to form NAD at 334, 340 or 365nm which is directly proportional to the AsAT units.

COMPOSITION

Tris buffer 80 mMol/L
a - ketoglutarate 12 mMol/L
L - aspartate 240 mMol/L
MDH 600 U/L
LDH 900 U/L
NADH 0.18mMol/L

Contains stabilisers, preservatives and
non-reactive fillers.

REAGENTS SUPPLIED
1.Cat. No. LS360 3x10mL
     Reagent 1   Buffer 3 x 9 mL
    Reagent 2   NADH 3 x 1 mL
2.Cat. No. LS 361 10x10mL
   Reagent 1   Buffer 10x9 mL
   Reagent 2   NADH 10x1 mL
3.Cat. No. LS 362 4 x 50 mL
Reagent 1   Buffer 4 x 45 mL
Reagent 2   NADH 4 x 5 mL

Preparation of Working Reagent
Mix R2 to  R1.

STABILITY OF REAGENT:
Unopened reagent is stable until expiry date marked on each label. Working reagent is stable for 30 days, when stored at 2-8C & protected from light.

SAMPLE
Use fresh serum (heparinised or EDTA Na+) plasma which shows no sign of     haemolysis. AsAT activity reduces at a rate of 8%/hour at  2-8°C and10%/hourat30°C.
Avoid fluoride plasma.

MANUAL METHOD

Temperature 37°C
Working Reagent 500 L
Sample 50 L
Factor 1746

Mix well. Take one minute reading at 340 nM after a delay of 60 seconds at 37C.
NOTE: Programme the analyser using system parameters. A specific programme              data sheet may be provided for each analyser upon request. Reagent,             sample volume and factor can be altered proportionately.

SYSTEM PARAMETERS
Reaction =    UV-Kinetic
Direction of Reaction =    Inverse
Temperature =    37°C
Wavelength =    340 nM
Factor % =    1746
Absorbance Range =    0-2°A
Cuvette Path Length =    1 cm
Delay Time Seconds =    60
Interval Seconds =    20
No. of Readings =    3
Linearity =    300 U/L
Reagent Volume         =    500µL
Sample Volume            =    50 l

RESULTS
Compute average rate of absorbance per minute x 1746 (at 340 nM).

EXPECTED VALUES

  TEMPERATURE 37°C
  MEN              IU/L 0-40
  WOMEN         IU/L 0-38

As with all diagnostic methods, the final diagnosis should not be made on the result of a single test as well as laboratory diagnosis must be confirmed with clinical manifestations.

LIMITATIONS
If the test exceeds the linearity limit dilute the sample with 0.9% Sodium Chlo­ride and rerun the assay. Multiply the result by dilution factor.
This reagent system is linear upto 300 U/L.

This methodology highly depends on accuracy and precision of instrument and professionals

QUALITY CONTROL
To ensure adequate quality control, each kit should be tested against a standard control sera. It should be realised that the use of quality control material checks both instrument and reagent function together. Factors which might affect the performance of this test include proper instrument function, temperature control, cleanliness of glasswares and accuracy of pipeting.
It is appropriate to establish each laboratory's accuracy constant and interpret values accordingly. Similarly, laboratory findings should be established by clinical manifestations.

WARNING
This reagent system is for in vitro Diagnostic use only. This reagent system is containing preservatives and components that have not established for safety if contacted on broken skin or eye or taken orally. In case of such incidents wash off with plenty of water, or consult a physician.

BIBLIOGRAPHY

  1. Jung K. Fechner C, Egger E, J. Cil Biochem(1976)14,53.
  2. Thefeld W, et. al., Dtsch. Med. Wschr. (1974)99,343.