Sperm Capture Using Aptamer Based Technology

Aptamers are short DNA molecules that have the molecular specificity and affinity recognition properties of antibodies; however, aptamer DNA molecules are more stable than antibodies for uses that involve "affinity" chromatography, since their complex, three-dimensional structures are capable of reforming after denaturation. Aptamers are reusable molecules that can routinely be chemically modified to increase their stability. The current study examined whether DNA aptamers can be developed to bind sperm heads and then be used to both identify and immobilize the sperm heads for purification and later DNA analysis. To date, research has identified several candidates with the ability to bind sperm under stringent and selective conditions. Recently, these aptamers were tested in a magnetic bead system with Biotin and Streptavidin linkers; they were found to selectively cluster sperm cells. This is the first aptamer-based system used in whole cell sperm capture. Research is ongoing for the purpose of fully characterizing and optimizing aptamers under various stringent and forensically relevant conditions. The goal is to develop an inexpensive and rapid system for sperm cell capture. As the project evolves, a full forensic validation study will be conducted to address reproducibility, sensitivity, reliability, and both mock and adjudicated forensic case samples. This system has the potential to enable high throughput systems for sperm capture and lysis of sperm cells based on magnetic beads, 96 well plastic plates, or other isolation techniques. 10 figures and 30 references