The DNA Analysis Unit primarily receives evidence related to homicides, robberies, sexual assaults and property crimes. The DNA Analysis Unit may perform biological screening on evidence to test for the presence of blood, semen, saliva, and/or urine. The samples can then be tested for two types of DNA extracted from body fluids, tissues, etc. The samples can be then be tested for Short Tandem Repeats (STRs) using Capillary Electrophoresis (CE) technology or they can be tested for STRs and SNPs using Sequencing technology. The Kern Regional Crime Laboratory's DNA Analysis Unit was one of the first public crime laboratories in the country to use probabilistic genotyping software for interpretation of DNA profiles and was also one of the first to utilize sequencing technology on casework samples.
The DNA Analysis Unit also has the capability of performing Kinship Analyses to test for maternity/paternity and or other possible genetic relationships which can be important in criminal and/or missing persons/unidentified remains cases.
Firstly, short tandem repeats (STRs) from nuclear (Autosomal) DNA are analyzed to yield DNA profiles that are most familiar to the general public. Secondly, STRs only on the Y-chromosome (Y-STRs), a strand of DNA that is only found in males, are analyzed to yield male-specific DNA profiles. Y-STR profiles are particularly important in cases where men are specifically suspected of a particular crime (e.g. some instances of sexual assault) where their DNA may be mixed with a high quantity of female DNA. The Kern Regional Crime Laboratory was also one of the first Crime Laboratories in the country to use probabilistic genotyping software for the interpretation of DNA profiles. Probabilistic genotyping is a more informative method for interpreting DNA profiles from multiple contributors and/or those that are from a low quantity.
The DNA Analysis Unit also has the capability of performing Kinship Analyses. Using the same STR testing, the laboratory can test for maternity/paternity and for other possible genetic relationships which can be important in criminal and/or missing persons/unidentified remains cases.