Development of an automated AmpliSeq™ library building workflow for biological stain samples on the Biomek® 3000.

Here, we present the development of an automated AmpliSeq™ (ThermoFischer, MA, USA) workflow for library building using the Biomek® 3000 Laboratory Automation Workstation (Beckman Coulter Inc., CA, USA), in which the total volume of PCR reagents and reagents for library preparation are reduced by one-half. The automated AmpliSeq workflow was tested using 43 stain samples (blood, bone, muscle tissue, semen, swab, nail scrape and cigarette butts) collected from crime scenes. The sequencing data were evaluated for locus balance, heterozygous allele balance and noise. The performance of libraries built with the automated AmpliSeq workflow using one-half of the recommended reagent volumes were similar to the performance of libraries built with the recommended (full) volumes of the reagents.

Design of a biological method for rapid detection of presence of PCR inhibitors in aged bone DNA.

BACKGROUND: Molecular human identification is one of the most important tests performed in forensic laboratories. Some of these tests are applied for identification of human remains from natural disasters, wars, etc., but problems may occur as a result of DNA degradation and external DNA contamination. We investigated effects of bacterial DNA on identifying the presence or absence of PCR inhibitors in aged bone DNA. METHODS: DNA samples were extracted from blood, bone remains and Escherichia coli. These DNA were amplified using human and bacterial specific primers. RESULTS: Using different blood, aged bone, and bacterial DNA dilutions along with PCR based methods; we checked their positive, negative effects, or detecting presence of inhibitors in aged bone DNA by PCR method. CONCLUSIONS: Our observation indicated that the addition of bacterial DNA could be a valid biological method for testing the quality of bone DNA to enable us to obtain a usable profile for the identification of human remains. This method will help to test the presence of inhibitors, quantity or even quality of DNA which are of importance in profiling archeological remains. Our method will help to determine if PCR failure is due to presence of inhibitors or lack of amplifiable DNA either because of degradation, minute amount or absence of human DNA.