title: 384-channel parallel microfluidic cytometer for rare-cell screening.
abstract: We have constructed a 384-channel parallel microfluidic cytometer (PMC). The multichannel architecture allows 384 unique samples for a cell-based screen to be read out in approximately 6-10 min, about 30-times the speed of a conventional fluorescence-activated cytometer system (FACS). This architecture also allows the signal integration time to be varied over a larger range than is practical in single-channel FACS and is suitable for detection of rare-cells in a high background of negatives. The signal-to-noise advantages have been confirmed by using the system to count rare clonal osteocytes in the most difficult early stages of an expression-cloning screen for the carboxy-terminal parathyroid hormone receptor (CPTHR). This problem requires finding several dozen positive cells in a background of one million negatives. The system is automated around a scanning laser confocal detector and a 96-tip robotic pipettor and can maintain in vitro cultures on-system in 384-well plates. It is therefore directly practical for biology applications using existing high-throughput culture facilities. The PMC system lends itself to high-sample-number cytometry with an unusual capability for time synchronization and rare-cell sensitivity. A limited ability to handle large sample numbers has restricted applications of single-channel FACS in combinatorial cell assays; therefore the PMC could have a significant application in high-throughput screening.
authors.affiliation: Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA02142, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Mckenna
authors.forename: A A
authors.initials: AA
authors.lastname: Selim
authors.forename: F
authors.initials: F
authors.lastname: Richard Bringhurst
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Ehrlich
mesh_terms: D000818:Animals; D002460:Cell Line; D002469:Cell Separation; D005434:Flow Cytometry / Q000379:methods*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D010011:Osteocytes / Q000166:cytology; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000235:genetics / Q000378:metabolism
chemical_list: D044168:Receptor, Parathyroid Hormone, Type 1