(62am) Quantifying Erythrocytes by Solution Resistance Measurement

Microfluidics is a rapidly growing field with applications ranging from protein or genomic analysis to inkjet printer technology. In the past, researchers have used many methods in quantifying cells and particles in a microdevice. Some of the methods are based on optical means, where a fluorescence signal is used to track the particle movement or to physically count the particles present. They both could be laborious, and time consuming. The purpose of this research is to relate DC solution resistance to the concentration of red blood cells within microchannels. A microdevice with a single, straight channel of 80µm in width, 1.5cm in length and 50µm in depth was fabricated with soft lithography and cast as a PDMS device. The device connections are shown in Figure 1. Resistance was measured over the channel with the erythrocytes using the Relation (1). Dextrose added buffers were used to quantify the dependence of solution conductivity alongside blood sample dilutions. DC voltages were applied lengthwise down the channel via electrodes and voltage change was measured across the resistor. This method has the potential to be used for quantifying cells at multiple outlet ports simultaneously with minimal analysis required.