(258g) Response of Human Erythrocytes to 10 Khz to 50 MHz Alternating Current Dielectrophoretic Stimulus

The use of human blood in medical diagnostics has proven to be an efficient means of obtaining a variety of information about the patient without being too invasive. According to The Merck Manual of Home Health Information, over 65 medical tests can be performed on human blood samples that provide health care workers with information such as specific enzyme, protein and vitamin levels as well as information about the composition of the patient's blood and the oxygen and carbon dioxide saturation levels (Merck Manual of Home Health Information, http://www.merck.com/mmhe/appendixes/ap2/ap2b.html). This information is extremely useful when making a diagnosis and in some cases can only be obtained by way of blood because saliva contains just over 20% of the proteins found in blood. Medical microdevices are poised to obtain quantitative diagnostic information from human blood with improvements in analysis time, reproducibility, and portability over tradition laboratory scale medical diagnostics. The ability to deduce membrane molecular expression would transform medical phenotyping and in the context of human blood would aid in determining a key medical factor - ABO blood type. Previous research by our group showed that O+ could be distinguished from A+, B+ and AB+ at a 95% confidence level and all four blood types could be distinguished at a 56% confidence level when subjected to a 1MHz alternating current field of field density 0.025Vpp/micron. This work is focused on qualitatively and quantitatively determining the differences between blood types when subjected to alternating current dielectrophoretic forces of frequencies between 10 kHz and 50 MHz. Blood was obtained from consenting donors of known blood type and centrifuged down to whole erythrocytes. The erythrocytes were then resuspended in an isotonically matched phosphate buffer saline before being injected into a custom fabricated microdevice. The microdevice was then hooked up to a signal generator that provided the specified frequency, 0.06Vpp/micron AC signal to the perpendicularly positioned micropatterned electrodes. A Zeiss Axiovert Inverted Light microscope was used to take still frame images of the erythrocytes in the microdevice every 15 seconds for 15 minutes. At the end of each experiment the still frame images were run through a customized Zeiss Automeasurement Program to identify each erythrocyte in the field of view as well as obtain quantitative information about the size, shape and placement of the cell. The impact of this research is a potentially easier way to determine the blood type of an unknown sample and later determine any disease markers.