Dry chemical reagent strip method for urine protein detection experiment

Summary

Heating can denature the protein and solidify it, and adding acid can make the protein close to the isoelectric point, which can lead to the precipitation of the protein. In addition, the addition of acid can also dissolve alkaline salts precipitation, this experiment from Mudanjiang Medical College undergraduate 5-year clinical laboratory guide

Operation method

Dry chemical reagent strip method for urine protein detection experiment

Principle

Proteins in urine were precipitated with tungstic acid and then quantified by the diuretic urea reaction.

Materials and Instruments

Sulfuric acid solution Sodium tungstate solution Distilled water

Move

I. Experimental reagents;

1. 1.75 mmol/L sulfuric acid solution

2、15g/L sodium tungstate solution

3, double urea reagent; take copper sulfate ( _CuSO420 ) 3.0 g dissolved in 500 ml of distilled water plus potassium sodium tartrate 9.0 g KI 50 g to make soluble, add 6 moL / LNaOH 100 ml of liquid water to 1000 ml mix. Store in closed polyethylene bottle.

4, protein standard solution (2.0 g / L) with accurate value of the mixture into the serum, 3 g / L of benzoic acid solution for dilution, released into 2.0 g / L concentration, stored for use.

Second, the experimental method:

1, 24 h urine specimen, (plus toluene antiseptic), mixed, the total amount of records, take a small amount of urine centrifuged with filter paper filtration.

2, first for protein characterization + - + + + + in 10 ml graduated centrifuge tube with urine 5 ml such as (+ + + + - ＋＋＋＋) then add urine in the tube lml distilled water 4 ml.

3, add 75mmol / L sulfuric acid 2.5ml mixed.

4, add sodium tungstate 2.5ml, mix thoroughly and stand for 10 minutes

5、Centrifuge the precipitate for 5 minutes, pour off the supernatant, retain the precipitate plus saline 1.0ml mix, for the determination of the tube.

6、Operate according to the following table

Measuring tube Standard tube

Pr standard solution 1.0

Bicondensation reagent (ml) 4.0 4.0

Mix well, water bath at 37°C for 30 minutes, colorimetry at 540nm, read SU

III.Calculation:

Total 24-hour urine protein (g) = (V/S) × 50 × (0.05/fixed tube urine volume (ml)) × (24 total urine volume/1000)

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