Master of Science in Biological and Agricultural Engineering (MSBAE)
Biological and Agricultural Engineering
An increasing number of laboratories are evaluating sample quality via motility analysis by means of computer-assisted sperm analysis (CASA) after sperm activation by manual dilution and mixing. Even with the use of CASA, due to user variation, there is a lack of control over the activation process, resulting in inconsistent motility analysis. Low sample volume (~1-2µL), and a short motility duration (burst motility of less than 15s) add to the complexity of these difficulties. The objectives of this study were to develop a microfluidic device with the capabilities to (1) standardize the method of activation for zebrafish sperm so that all cells in a sample are subjected to the conditions needed to activate in a reproducible way, (2) reproducibly enable motility analysis of the activated sample within 5 s after activation without the interference of bulk fluid flow, and (3) facilitate the generation of activation curves by relating osmolality of the sample solution to percent motility at the time when motility analysis was performed. The device described here is a three-inlet microfluidic platform fabricated from polydimethylsiloxane (PDMS) bound to a glass substrate with a microfabricated gold floor electrode for osmolality detection. A passive micromixer is utilized to activate sperm samples, and a novel flow control system was designed to aid with the demands of sample analysis. The device demonstrated consistent zebrafish sperm activation and osmolality detection. The device was also able to consistently reach flow cessation in under 1s, allowing for rapid analysis of the sample. This device represents a pivotal step in streamlining methods for consistent, rapid assessment of sperm quality for zebrafish and other aquatic species. The capability to rapidly activate sperm and consistently measure motility with CASA using the microfluidic device described herein will help improve the reproducibility of studies on germplasm physiology.
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Beckham, Jacob Ethan, "Microfluidic Device for Motility and Osmolality Analysis of Zebrafish Sperm" (2016). LSU Master's Theses. 1722.
Monroe, W. Todd