The release of adenosine triphosphate (ATP) from red blood cells (RBCs) flowing through PDMS microchannels has been determined as a function of channel cross-sectional area using a design containing a channel that narrows uniformly. ATP, released from the RBCs in response to the mechanical deformation of their cell membranes, increased as the channel cross-section decreased. One sample of rabbit RBCs released 1.16 ± 0.11, 1.92 ± 0.14 and 2.09 ± 0.10 μM ATP as the median cross-sectional area decreased from 4314 to 3192 to 2052 μm2, respectively. Numerous samples (n=6) displayed the same trend. Incubating a sample of RBCs with diamide, a substance known to stiffen cell membranes without harming the cell cytosol, provided evidence that no cell lysis occurred in the microchip device. This novel use of lab-on-a-chip technology allows for channel designs that enable an in vitro study of physiological events that occur in the microcirculation.
Price, A. K., R. S. Martin, D. M. Spence
J. Chromatogr. A