In this study, a method for analyzing forensically significant Short Tandem Repeat (STR) DNA markers using MALDI-TOF-MS will be designed and tested. Although advances in instrumentation have resulted in an increase in the mass limit for MALDI analysis, traditional STRs are still too large for even modern MALDI-TOF instrumentation. Reduced size STR primers (miniSTR) will be used to address this issue. MiniSTR primers are designed to bind as close to the STR repeat region as possible, creating a smaller PCR amplicon than traditional STRs, and will fit within the the mass limitations of MALDI. New CODIS loci have been recently added to the collection of forensic database markers, and the analysis of these loci will be conducted. These loci include D1S1656, D2S441, and D2S441. This will follow analysis of a limited number of previously tested loci with the same method and a comparison of the findings to previously published results. Previously examined loci will include TH01, vWA, and TPOX. After reduced-size STR primers are designed for the selected loci and tested using real-time PCR analysis, human DNA standards will be amplified and purified to remove interferences such as salts and excess primers and dNTPs. The matrix used will be 3-hydroxypyridine- 2-carboxylic acid (3-HPA) and the samples will be analyzed on the Axima MALDI-TOF-MS. The mass of the amplicons will be calculated and compared to expected mass to evaluate the precision and accuracy of the method. Lastly, the method will be adapted as a new teaching tool for use in the forensic body fluid analysis laboratory class at York College, utilizing the current instrumentation available in the lab.

Development of an analysis method of forensically significant reduced-size STRs by MALDI-TOF-MS

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.