M. Chengalvala et al., A multi-well filtration assay for quantitation of inositol phosphates in biological samples, J BIOCH BIO, 38(3), 1999, pp. 163-170
The quantitation of inositol phosphates (IPs), mediators of certain signal
transduction processes, typically involves laborious and time consuming con
ventional ion-exchange chromatography procedures. We have developed a high
throughput microtiter plate-based IP assay that utilizes vacuum rather than
gravitational flow and has significant advantages over existing methods. T
he response of recombinant HEK-293 cells expressing human LHRH receptor cDN
A to LHRH agonists was used as a model system to develop the assay conditio
ns. Cell lysates containing labeled IPs were applied in 96-well plates fitt
ed with filtration discs containing regenerated Dowex AG1-X8 resin. Specifi
cally bound inositol phosphates were eluted with 1 M ammonium formate in 0.
1 M formic acid directly into a fresh 96-well plate and an aliquot of the e
luate from each well is transferred into a 96-well plate and counted. The r
esults were comparable to those obtained with the conventional column metho
d and the variation among replicates was significantly improved. This assay
facilitates rapid quantitation of inositol phosphates from a large number
of samples with relative ease and reduced generation of radioactive waste.
(C) 1999 Elsevier Science B.V. All rights reserved.