Identification of human urine stains on cloth.

Experimental stains of human urine prepared on 4 different types of cloth and cloth stains in practical cases were examined by 2 methods which have been established in this laboratory. A chemical method determining uric acid and urea nitrogen content and an enzyme-linked immunosorbent assay (ELISA) to determine uromucoid. The former method uses the quotient uric acid/urea nitrogen as an indicator and the latter the quotient ELISA score/protein concentration. All stains were identified as human urine stains by both methods when the specimens were taken from the centre of the stains but when taken from the periphery some of them, especially those on cloth such as cotton or silk, could not be identified as human urine stains. These results indicate that the central part of stains should be preferentially used for the identification of human urine stains, especially those made on cloth such as cotton or silk.