Deformation of a single mouse oocyte in a constricted microfluidic channel
Single oocyte manipulation in microfluidic channels via precisely controlled flow is critical in microfluidics-based in vitro fertilization. Such systems can potentially minimize the number of transfer steps among containers for rinsing as often performed during conventional in vitro fertilization and can standardize protocols by minimizing manual handling steps. To study shape deformation of oocytes under shear flow and its subsequent impact on their spindle structure is essential for designing microfluidics for in vitro fertilization. Here, we developed a simple yet powerful approach to (1) trap a single oocyte and induce its deformation through a constricted microfluidic channel, (2) quantify oocyte deformation in real time using a conventional microscope and (3) retrieve the oocyte from the microfluidic device to evaluate changes in their spindle structures. We found that oocytes can be significantly deformed under high flow rates, e.g., 10 μL/min in a constricted channel with a width and height of 50 and 150 μm, respectively. Oocyte spindles can be severely damaged, as shown here by immunocytochemistry staining of the microtubules and chromosomes. The present approach can be useful to investigate underlying mechanisms of oocyte deformation exposed to well-controlled shear stresses in microfluidic channels, which enables a broad range of applications for reproductive medicine.
KeywordsOocyte deformation Spindle damage Single cell trapping Microfluidics
Utkan Demirci acknowledges that this work is supported by the National Institutes of Health award (R01 EB015776). We would like to acknowledge Dr. Aida Nureddin for her significant contributions to this work. ZhengYuan Luo acknowledges financial supports from China Scholarship Council. This work was also partially supported by Swedish Research Council Vetenskapsrådet.
Conflict of interest
Dr. Utkan Demirci is a founder of and has an equity interest in: (1) DxNow Inc., a company that is developing microfluidic and imaging technologies for point-of-care diagnostic solutions, and (2) Koek Biotech, a company that is developing microfluidic IVF technologies for clinical solutions. Dr. Utkan Demirci’s interests were viewed and managed by the conflict of interest policies.
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