A New Screening Method for Cystinuria

The new kit (Urocystin) presented here utilizes the dark brown coloration which a neutral aqueous solution of cystine develops rapidly upon addition of nickel ion and sodium hydrosulfite (Na2S2O4). What is needed is pouring 4 ml of the urine sample into the kit, and the kit is able to judge without fail any urine sample with a cystine concentration of 50 µg/ml or more as positive. No pretreatment of the sample is necessary. The kit contains no hazardous reagents at all. The kit has thus turned screening of cystinuria into an extremely simple affair.