ラテックス凝集免疫比濁法を用いた吐物証明法に関する法科学的研究

Abstract

For forensic science, vomit identification is essential for crime scene reconstruction in various crimes, such as murder, abuse and drug poisoning. In order to develop a rapid and simple method for vomit identification, we modified the protocol for pepsinogen I (PGI) and pepsinogen II (PGII) detection kits based on latex agglutination turbidimetric immunoassay for clinical examination. Although these kits are assumed for using expensive automated biochemical analyzers, we examined the analysis on a general absorption spectrometer. As a result, PGI and PGII could be detected in up to 1000-fold diluted human gastric juices and mock casework samples by our modified method. However, crossreactions with urine for PGI and semen for PGII were observed. If urine and/or semen is considered to be mixed in the casework samples, urine and/or semen tests should be performed in addition to PGI and PGII tests. Aged gastric juices stored up to 12 months were also detected, suggesting that the present method could be applicable to aged samples. Because PGI and PGII can be detected within approximately 1 hour by simple operations using an absorption spectrometer, the present method has the potential to be applicable to forensic caseworks as a new tool for vomit identification.