Plug flow cytometry: An automated coupling device for rapid sequential flow cytometric sample analysis.

BACKGROUND

The tools for high throughput flow cytometry have been limited in part because of the requirement that the samples must flow under pressure. We describe a simple system for sampling repetitively from an open vessel.

METHODS

Under computer control, the sample is loaded into a sample loop in a reciprocating eight-way valve by the action of a syringe. When the valve position is switched, the plug of sample in the sample loop is transported to the flow cytometer by a pressure-driven fluid line. By coupling the plug-forming capability to a second multi-port valve, samples can be delivered sequentially from separate vessels.

RESULTS

The valve is able to deliver samples at rates ranging up to about 9 samples per minute. Each plug of sample has uniform delivery characteristics with a reproducible coefficient of variation (CV). Even at the highest sampling rate, carryover between samples is limited.

CONCLUSIONS

Plug-flow flow cytometry has the potential to automate the delivery of small samples from unpressurized sources at rates compatible with many screening and assay applications.