224. Determining the effects on yeast cell size and count when varying orifice tube size using the Coulter principle

Ashley Lovering (1), Jack Saad (1), Rick Shimkus (1); (1) Micromeritics Instrument Corporation, Norcross, GA, U.S.A.

Analytical
Supplier Poster

Yeast cell health and reproduction rates are commonly characterized using electric sensing zone (ESZ) technology, which is based on the Coulter principle. This technique involves two cells of electrolyte solution separated by an insulating barrier through which there is a cylindrical orifice. The reservoirs have opposite electrical charges, causing an electrical current to flow through the orifice channel, while a pumping mechanism also causes the electrolyte to flow through the same orifice channel. As electrolyte is flowing, yeast cells present in the electrolyte will pass through the orifice displacing, electrolyte and creating an resistance in the electrical current. The size of the resistance is proportional to the volume of the yeast cell, and the number of times a resistance appears correlates to yeast cell count. Choosing the appropriate orifice size for the yeast cells being characterized is vital to collecting accurate data. Each orifice size has a specific size detection range. Using varying extreme size differences in orifices that have overlapping size ranges to characterize common yeast cells used in beer brewing, size and count data are compared and contrasted.

Ashley Lovering obtained her ACS-certified B.S. degree in chemistry, with a business concentration, from the Georgia Institute of Technology. As an undergraduate student, she worked as a laboratory technician in the metal energy and electroplating labs at Delta Airlines, where her responsibilities included analyzing plasma spray samples and maintaining electroplating tanks. Ashley joined Micromeritics Instrument Corporation in 2014 as a lab analyst with their contract analytical laboratory, Micromeritics Analytical Services. She specializes in a variety of material characterization techniques, including particle size distribution by electro-zone sensing, surface area by gas adsorption, particle shape using dynamic image analysis, and density by gas displacement.