Evidence Screening & Differential Extraction For DNA Analysis

More than 200,000 rapes and sexual assaults are reported each year in the United States. Worldwide, in excess of 840,000 cases involve sexual assault⁴. Every 107 seconds, another American is sexually assaulted. South Africa records the highest rates of rape in the world. According to children’s welfare groups, a woman is raped every 17 seconds in South Africa.

DxNow, in collaboration with The Demirci Bio-Acoustic MEMS in Medicine Labs (BAMM) at Stanford Medicine, has developed microfluidic-based platforms for the capture and sorting of a diverse type of cells and pathogens by utilizing highly specific recognition elements including antibodies and carbohydrates. These platform technologies have the potential of being deployed for the detection, capture and quantitation of multiple cell types from unprocessed samples. We have now applied these state-of-the-art technologies to selectively capture sperm from complex bodily fluids, a step which is crucial in forensic DNA analysis of sexual assault samples. Processing of sexual assault evidence generally requires separation of the victim’s cells (epithelial) from the perpetrator’s cells (sperm) and involves time consuming steps of selective cell lysis, centrifugation and separation into female and male DNA fractions (a process known as differential extraction). DxNow technology will provide a catalyst in helping to reduce DNA forensic backgrounds in cases involving sexual assault evidence. Methods for rapid and efficient processing of sexual assault evidence will accelerate forensic investigation and reduce casework backlogs.

⁴ http://www.rainn.org/statistics

DxNow leverages its expertise and proprietary technology in biology, microfluidics, imaging, surface chemistry and product design to supply tools for the research community. For example, both the FERTILE™ and FERTILE PLUS™ microfluidic devices may have applications in sperm toxicity for pharmacological R&D, sperm inhibition related to contraception, and genetic and epigenetic influences on sperm function. DxNow’s innovative proprietary lensless holographic shadow imaging in combination with modified surface chemistry has broad application in cell-based and particle-based capture assay detection.

Building on our expertise in cell sorting tools incorporating shadow imaging for detection and characterization of cells, we are developing medical diagnostic devices leveraging these technologies, along with microfluidic integrated biosensors, to capture and quantify cells from unprocessed whole blood or other body fluids. This healthcare platform technology addresses significant underserved clinical needs in the home and primary care settings for innovative, inexpensive, accurate and easy-to-use point-of-care diagnostics products.

This platform will deliver accurate, rapid and inexpensive test results, minimizing unnecessary and costly ER visits and hospitalizations. Specifically, our solutions consist of (i) a disposable single use microfluidic cartridge to capture WBCs and neutrophils and (ii) a portable, easy-to-use lens-free shadow imaging system to rapidly quantify captured cell counts. The easy-to-collect measurements and regular monitoring capabilities will provide much needed, timely treatment of patients before their conditions become acute.

Our lead product focuses on significant underserved medical needs in end-stage renal disease; specifically, addressing critical clinical barriers to more widespread use of peritoneal dialysis. Peritoneal dialysis is a preferred treatment modality that can be performed in the home setting, but is often not utilized due to the risk of peritonitis. By leveraging our technologies, we are delivering an inexpensive, disposable diagnostic that can be used in the home setting by patients to easily capture and analyze neutrophils from their dialysate to detect early indicators of peritoneal infection. Early detection of infections at their onset will enable clinicians to start early treatment, providing significant clinical benefits:

• Detecting infection at the onset and preventing the infection from developing to the chronic phase
• Monitoring and managing peritoneal dialysis therapy more easily within the home care environment
• Minimizing repeat infections, which can lead to peritoneal membrane degradation and forcing patients to switch to the more expensive and less convenient hemodialysis treatment.

Beyond monitoring for peritoneal infection, this proposed platform has broad potential application in monitoring patients receiving chemotherapy and transplants, where the need for a rapid and complete blood count is applicable, as well as detecting catheter infections rapidly in many other clinical procedures.