ANYL 3 |
| A microfluidic device that generates spatially distinct solution environments by emitting fluids from 16-98 different microchannels into a solution-filled macroscopic chamber is presented. Patch-clamped cells are scanned across the stream allowing controlled exposure with ms-resolution to a large number of ion channel activators and inhibitors. Algorithms, and methods were developed to synthesise complex chemical waveforms around the patch-clamped cell. We demonstrate that GABAA receptors can be controlled to display high or low EC50-values, depending on input function. Inhibition is dramatically dependent on how the different desensitized states are populated. Furthermore, we report that GABAA receptors form a short-term memory circuit when integrated with a scanning-probe microfluidic device. Receptor activators provided by the microfluidic device define and periodically update the data input which is read and stored by the receptors as state distributions. The memory is discharged over time, and lasts for seconds to minutes depending on the input function. The function of the have striking similarity to a dynamic random access memory (DRAM). Multiplexed biohybrid memories may form the basis of large-scale integrated biocomputational/sensor devices using chemical signals as input signals. I will also describe a microfluidic sample preparation method for membrane proteins. The method allows for immobilization of proteoliposomes carrying functional membrane proteins that can be digested in multi-step protocols to yield peptide fragments that are analyzed by ESI-MS. The method conserves protein mass, and concentration, and can yield protein structure with high sequence coverage (close to 100%), and high sensitivity (down to about 100 protein copies/cell). |
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Honoring Andrew Ewing, Recipient of the Chemical Instrumentation Award
8:30 AM-10:50 AM, Sunday, 10 September 2006 Moscone Center -- Room 123, Oral
Division of Analytical Chemistry |