Urine Sugar Screening Laboratory
Urine Sugar Screening Laboratory
In the reagent tape there is no glucose oxidase (GOD) peroxidase (POD) pigment original and weak acidic buffer composed of the reaction reagent and as the base color of the blue or yellow pigment, this test tape immersed in urine, such as urine containing glucose, due to glucose oxidase (GOD), glucose oxidized to glucuronic acid and hydrogen peroxide (H2O2) H2O2 in peroxidase (POD) under the action of the release of new ecological oxygen to oxidize the pigment original and the color development. H2O2 is oxidized to glucuronic acid and hydrogen peroxide (H2O2) under the action of peroxidase (POD), and the new ecological oxygen is released to oxidize the pigment and show the color, this experiment is from the Mudanjiang Medical College, undergraduate 5-year clinical laboratory guide.
Operation method
Urine Sugar Screening Laboratory
Principle
In the reagent tape without glucose oxidase (GOD) peroxidase (POD) pigment source and weakly acidic buffer composed of reaction reagents and as a base color of blue or yellow pigment, the test tape immersed in urine, such as urine containing glucose, due to glucose oxidase (GOD), glucose oxidized to glucuronic acid and hydrogen peroxide (H2O2) H2O2 peroxidase (POD) under the action of the release of new ecological oxygen to oxidize the pigment source and show the color, indicating the reaction is as follows: glucose + O2 (from air = = gluconic acid ten 2H2O, pigment source (colorless) and oxidation of color. POD) under the action of the release of new ecological oxygen to oxidize the pigment original color, indicating the following reaction: glucose ＋ O2 (from the air = = = gluconic acid ten 2H2O, pigment original (colorless) ten H2O2 → oxidized pigment (color) + 2H2O pigment original commonly used for the oxidation of o-toluidine into the blue, while some use potassium carbide, the latter was oxidized into the free iodine in brown. Experimental operation: dip the test strip into the urine, remove it after 5 seconds and compare it with a standard color plate in natural light. Determination of the end, if the color remains unchanged for the negative, if the pigment is o-aniline, blue for positive. If the pigment is potassium iodide, it is positive if it shows brown color. Move Glucose oxidase method: same principle as glucose oxidase test strip method. Caveat I. Glucose oxidase test strip method1、The sensitivity of this method is 250mg/L, and it has high specificity for glucose, but not for other sugars. 2， pay attention to the enzyme reaction time of the test strip, according to the specified time and the standard plate colorimetric reagents can not be exposed to air and sunlight, and shall not be in contact with gas, should be stored in a cool dry place, the validity of more than half a year. 3， if you take a lot of vitamin C and the application of mercury diuretics and other drugs, can be a seemingly negative reaction. In order to eliminate the inhibitory reaction of vitamin C, the patient before the test, at least must stop using vitamin C in more than 24h, generally stop using vitamin C 3 days.Second, quantitative urine glucose test1, the correct implementation of the urine specimen dilution and aspiration techniques, the container must be calibrated. 2， other precautions and glucose oxidase test strip method is the same. For more product details, please visit Aladdin Scientific website.
Experimental operation: the measurement of the enzyme phenol mix, reagents in the 37 ℃ water bath box preheating 10 minutes. And the urine specimen diluted 10 times, and then according to the table operation
Glucose oxidase colorimetry procedure
Measuring tube Standard tube Blank tube
Diluted urine, 20 microliters.
Glucose standard - 20 microliters -
Enzyme-phenol mix 4 ml 4 ml 4 ml
After mixing, keep warm in a 37℃ water bath for 5 minutes, adjust the zero with a blank tube, and compare the color at 500nm.
Calculation: Glucose (20mol/L) = (Absorbance of measurement tube / Absorbance of standard tube) × 5.55
Lab report: morning urine (or random urine) specimen: grape method × 2umol/L