Social and Behavioral Sciences Commons^™

Optimization Of Microfluidic Device Methodology For Optical Trapping Epithelial Cells In A Mixture, Brittney N. Hackworth

Master of Science in Forensic Science Directed Research Projects

Evidence containing biological mixtures can make DNA interpretation more difficult due to ambiguous allele calls and artifacts that may be present within electropherograms. Separating out these cell mixtures can be advantageous to the analysts’ analysis methods for identifying STR profiles with higher accuracy. A potential cell separation method that could be implemented in the beginning of the forensic DNA workflow is optical trapping.

This research utilized a 5W ytterbium linearly polarized laser split into two optical traps, paired with a microfluidic device to isolate spermatozoa and vaginal epithelial cells from a 1:1 mixture of vaginal fluid and 1:20 diluted seminal …

Optimization Of A Microfluidic Device For Cell Capture Using Optical Trapping, Samantha C. Pagel

Master of Science in Forensic Science Directed Research Projects

Biological mixtures which result from evidence produced in sexual assault cases are one of the most common types of mixtures observed in forensic biology casework and have contributed to evidence backlogs across the country. In the forensic community, this has highlighted the need for a more efficient cell separation method at the beginning of the DNA analysis workflow than the currently accepted method. One promising novel front-end cell separation technique is optical trapping. In heterogeneous mixtures, optical tweezers have been demonstrated to manipulate and isolate cells of interest from other cell types.

For this research, a range of 5 to …

Creation And Optimization Of An Optical Trapping Microfluidic Device For The Separation Of Mock Forensic Sexual Assault Samples, Mackenzie Lally

Master of Science in Forensic Science Directed Research Projects

Cell mixtures are often seen in forensic samples and commonly involve sexual assault cases where mixtures of sperm cells and vaginal epithelial cells are frequently encountered. This produces challenges in downstream analysis in the form of STR mixture profiles. The only method currently in use in crime laboratories for front-end sperm and epithelial cell separation is differential extraction. This method often results in STR mixture profiles due to carryover into both the male and female fractions and suffers from a wide range of efficiency depending on the laboratory or individual processing the sample. Optical trapping offers an alternative method for …