Yellow calendar salicylic acid method

The most common qualitative methods of urine protein are test paper method, heated acetic acid method and sulfosalicylic acid method. The test paper method can only detect albumin by using the protein error principle of pH indicator. The heating acetic acid method is based on the principle that protein is heated, boiled, denatured and solidified in an acidic environment (pH 4.7). Sulfosalicylic acid method, also known as sulfosalicylic acid method, is the principle that the positively charged amino group of urine protein is combined with negatively charged sulfosalicylic acid to form insoluble protein salt precipitation in an acidic environment slightly below the isoelectric point of protein. Sulfosalicylic acid is an alkaloid, which can precipitate with protein and react with albumin, globulin, glycoprotein and peridin, so it has high sensitivity and is recommended as a confirmation test of urine protein.