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Preparation and characterization of calibration beads for sorting cells expressing a β-lactamase gene reporter

✍ Scribed by Michael E. Cunningham; Marianna Kapitskaya; Konstantin Petrukhin; Bohumil Bednar


Publisher
John Wiley and Sons
Year
2005
Tongue
English
Weight
710 KB
Volume
65A
Category
Article
ISSN
0196-4763

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✦ Synopsis


Abstract

Background

Modern drug discovery has been based on high‐throughput screening using whole‐cell assays. A prominent role has been assigned to the reporter gene technology based on a β‐lactamase and the fluorogenic substrate CCF2. Successful application of this technology requires fluorescence‐activated cell sorting. We describe the preparation and characterization of calibration beads for sorting cells expressing the β‐lactamase gene using the CCF2 substrate.

Methods

To model Förster resonance energy transfer (FRET) between the coumarin donor and the fluorescein acceptor of the CCF2 reporting dye, we used activated polystyrene beads with primary amino groups. Donor and acceptor fluorophores were attached to the beads at different ratios via succinimidyl esters. The beads were characterized with a fluorescence plate reader and a flow cytometer.

Results

We prepared polystyrene beads with five different ratios of donor and acceptor fluorophores and beads that carried a donor or a receptor fluorophore alone. Fluorescence measurements demonstrated that the prepared beads well represent the FRET of CCF2 substrate.

Conclusion

We have demonstrated that the prepared beads can be successfully used for the setup of fluorescence‐activated cell sorting to sort cells with CCF2 reporter substrate and the β‐lactamase reporter gene. © 2005 Wiley‐Liss, Inc.