Glucose ( GOD /POD )

 Clinical significance : -

                                       Glucose is the major carbohydrate present in blood. Its oxidation in the cells is the source of energy for the body. Increased level of glucose are found in Diabetic Mellitus , hyperparathyroidism ,  pancreatitis , renal failure . Decrease level are found in insulinoma ,  hypothyroidism , hypopituitarism and extensive liver disease.

 Principle :-

                    Glucose is oxidised to gluconic acid and hydrogen peroxide in the presence of glucose oxidase. Hydrogen peroxide further  react with phenol and 4-aminoantipyrine by the catalytic action of peroxidase to form red coloured quinonimine  dye complex. Intensity of the colour formed is directly proportional to the amount of glucose present in the sample. 

 Material required :-

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

 Normal Value :- 

                             70 - 120 mg/dl   (FBS)

                             Up to 150 mg/dl  (RBS & PPBS ) 

Sample :-

              Blood should be collected in a clean dry container. Serum or plasma should be separated from the cells at the earliest possible ( within 30 minutes),  as the rate of glycolysis is approximately 7 mg percent  per hours  at room temperature. Sodium fluoride is referred as anticoagulant due to its anticoagulant  activity . The higher concentration of sodium chloride more than 10 mg/dl blood should be avoided as it may  inhibit the colour development. Glucose is stable for  24 hours in neatly separated plasma and serum . If the estimation is not possible within 24 hours then the specimen should be preserved at-10' C and should be used within 30 days.

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	-	10 ul	-
Sample	-	-	10ul

 Mix well  and  incubate  at  37 ‘ C for 10 mins. Measure absorbance of the standard ( Abs . S ) and Test ( Abs . T ) against Reagent blank at 520 nm.

 

   Calculation  :-

                                              Abs . T

                    Glucose ( mg/dl ) =    ..............  * 100

                                              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. Re-plug the Glucose standard vial after use.

 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