MICROFABRICATED LOW-COST COUNTING CHAMBERS FOR STANDARDIZED ESTIMATION OF SPERM CONCENTRATION

Evaluation of sperm concentration is essential for research and procedures involving artificial fertilization, cryopreservation, and assessment of sperm quality. Microfabrication technologies have shown tremendous potential to rapidly prototype and fabricate devices to assist reproduction and fertility research, however, such utility has not yet been made available for reproduction laboratories. The goal of this work was to evaluate the feasibility of using microfabrication techniques to produce counting chambers for estimation of sperm concentration. Zebrafish (Danio rerio) sperm were used as a model for evaluation of functionality of the chambers. These microfabricated enumeration grid chambers (MEGC) (Figure 1) were composed of a polydimethylsiloxane (PDMS) coverslip with grid patterns (100 × 100 μm) and a PDMS base platform to create a known volume with a 10-μm height to restrict sperm cells to a single layer. The cell counts estimated by two of three early prototype MEGC devices tested were not significantly different from the control device, a commercially available Makler^® chamber. The material cost for a MEGC was < $0.1 compared to ~ $100 for a standard hemocytometer and $700 for a Makler^® counting chamber. This study demonstrates the feasibility of microfabrication in creating low-cost counting chambers to enhance standardization and strengthen interdisciplinary collaborations. Such device can be applied in research, hatchery management, genetic breeding programs, and commercial aquaculture applications.