Uric Acid ( Uricase Method )

 Clinical Significance :-

                         Uric acid is the end product of the purine metabolism. Uric acid is the excreted to a large degree by the kidneys and to smaller degree in the intestinal tract by microbial degradation . Increased level are found in gout,  Arthritis,  Impaired renal function and starvation. Decrease  level are found in Wilson's disease and yellow atrophy of the liver.

Principle :-

             Uricase convert uric acid to allantoin and hydrogen peroxide. The hydrogen peroxide  formed further  react with a  phenolic compound and 4-aminoantipyrine by the catalytic action of peroxidase to form a red colour   quinonimine  dye complex.  Intensity of the colour formed is   directly proportional to the amount of uric acid present in the sample.

 Material required :-

• Clean and dry glassware.                                     
• Laboratory glass Pipettes or  micro Pipettes and tips. 
• Colorimeter.

 Normal Value :- 

                             4.0 - 7.2 mg/dl   (Male)

                             2.7 - 6.5 mg/dl   (Female) 

Sample :-

        Unhemolysed Serum, Heparinized/EDTA Plasma.

Procedure :-

                       Pipette into clean and dry test tubes labeled as Blank ( B ) , Standard ( S ), and Test ( T ) :

Addition           Sequence	B	S	T
Reagent	1ml	1ml	1ml
Standard	-	25 ul	-
Sample	-	-	25ul

 Mix well  and  incubate  at  37 ‘ C for 05  mins. Measure absorbance of the standard ( Abs . S ) and Test ( Abs . T ) against Reagent blank at 505 nm.

 

   Calculation  :-

                                              Abs . T

                    Uric Acid ( mg/dl ) =    ..............  * 6

                                              Abs . S   

Preparation and reagent and stability :-

                                        All Reagent are ready to use and are stable till the expiry date mentioned on the label , when stored at 2' to 8' C.

Quality Control :-

                  For accuracy it is necessary to run known controls with every assay.

Limitation & Precautions :-

 

1. Storage conditions as mentioned on the kit to be adhered.
2. Do not freeze or expose the reagent to high temperature and protect from direct as it may affect the performance of the kit.
3. Use clean glassware free from dust .
4. Before the assay bring all reagents to room temperature.

 General System Parameters:-

          Reaction type           : End point 

          Wave length             : 505 nm ( 490 - 530 nm )

          Temperature             : 37'C

          Incubation              : 10 minutes 

          Reagent Volume          : 1.0 ml

          Sample Volume           : 10 ul 

          Standard concentration  : 100 mg/dl

          Zero setting            : Reagent Blank

          Light Path              : 1.0 cm