A NEW INDIVIDUALIZATION MARKER OF SWEAT - DEOXYRIBONUCLEASE-I (DNASE-I) POLYMORPHISM

We have confirmed for the first time, both biochemically and immunolog ically, the existence of deoxyribonuclease I (DNase I) in human liquid sweat. Isoelectric focusing of sweat samples on polyacrylamide gels ( pH 3.5 to 5), followed by dried agarose film overlay detection, was us ed to determine the phenotypes of sweat DNase I. Because this detectio n method not only had high sensitivity, but also high band resolution, it was possible to determine DNase I types from sweat samples of 50 t o 100 mu L. Pretreatment of sweat samples with sialidase was essential for typing to enhance markedly the sensitivity accompanied by simplif ication of the isozyme pattern. The DNase I types in all sweat samples were consistently related to the types found in corresponding blood, urine, and semen samples. DNase I typing could, therefore, provide a n ovel. discriminant characteristic in the forensic examination of sweat .