Principles of quality management in conducting forensic biological examination of material evidence

The publication describes a method for conducting intra-laboratory quality control when determining various levels of PSA and IgG concentrations in aqueous extracts from semen and blood stains dried on gauze by quantitative enzyme immunoassay, used to determine the presence of sperm and blood species. It has been established that in-laboratory quality control of samples obtained as a result of measuring the concentration of PSA and IgG in duplicates is rationally carried out using the Dahlberg formula, which makes it possible to calculate the indicators of standard uncertainty: SD and CV%. As a result of the conducted study of the quality of interpretation of measurement results in aqueous extracts from semen and blood stains by quantitative enzyme immunoassay using a consistent Clark error grid, data on the acceptable error value for zone «A» were obtained, which can be taken into account when conducting forensic examinations of material evidence.