The Daily Bulletin Archive

Casey Brown, a master's degree candidate of forensic science in the Chemistry Department at Buffalo State, will present her master's defense seminar, "Microfabrication of Single Cell Hydrogel Array for Studying Cell Volume Regulation," at 12:30 p.m. Thursday, May 2, in Science Building 272. This seminar series is supported by the Auxiliary Services Grant Allocation Committee, the Vice President for Student Affairs Office, and the Faculty-Student Association. The seminar abstract follows.

Abstract
In response to external stimuli, cells alter their chemical and physical properties. One interesting physiological phenomenon is cell volume regulation. This particular mechanism is critical for cell survival and responsible for maintaining cell volume homeostasis after osmotic shock. Many efforts have been made to develop techniques of measuring cell volume change; however, previously developed techniques lack the ability to screen malfunctioning single cells among a population of cells with high throughput. Probing the behaviors of single cells can provide valuable information that can be hidden by the averaged information of a population of cells.

By using a polydimethylsiloxane (PDMS) template and photocrosslinkable hydrogel precursor solution, we have created a new method of fabricating a single cell array based on hydrogel. The hydrogel array was constructed on the glass, and the glass surface within the wells was treated with fibronectin to promote cell adhesion. The size of the hydrogel microwell was controlled to contain a single cell. Madin-Darby Canine Kidney (MDCK) cells were grown in the well array. Greater than 50 percent of the array was occupied by single cells. After exposure to hypotonic solution, a cell volume regulation experiment was performed using the cells loaded with Calcein-AM dye. Since the microwell array can precisely locate the positions of individual cells, dynamic behaviors of same single cells could be conveniently traced over a long period of time. By exploring volume regulation phenomena using our single cell array, it is possible to screen malfunctioning cells in high throughput and therefore clarify the cause of heterogeneous responses of single cells. In addition, the cells in the well array can be easily accessed for further genomic or proteomic analysis.