WeO-05


FEMTOMOLE LEVEL SEQUENCING OF PEPTIDE MIXTURES USING NANOFLOW ELECTROSPRAY

J. I. Langridge, T. McKenna, S. A. Jarvis and C. J. Hughes

Micromass UK Ltd., Tudor Road, Altrincham, Cheshire, WA14 5RZ


Low flow rate electrospray (nanoelectrospray) sources have been described previously by M. Wilm(1) and R. Caprioli(2). In this study we describe a Nanoflow electrospray probe developed for single and triple quadrupole mass spectrometers, and its application to the analysis of protein digests.

The main difference between the Nanoflow electrospray probe and a standard electrospray probe is the use of small (1 or 2µm) internal diameter sprayer capillaries. These capillaries permit stable electrospray at flow rates in the range 10nL/min to 30nL/min, yet yield similar ion currents to that produced at standard electrospray flow rates (~5µL/min). Consequently, equivalent data may be obtained from a given sample concentration by consuming less than one hundreth of the sample previously required.

Data will be presented showing the analysis of unseparated tryptic digests, allowing the sequencing of peptides from a mixture at the low femtomole level, using only 1-2µL of sample.

References

1. Matthias Wilm, Matthias Mann (1994) Int. J. Mass Spec. Ion Processes 136, 167-180.
2. R. M. Caprioli, M. E. Emmett, P. E. Andren Proceedings of the 42nd ASMS Conference on Mass Spectrometry and Allied Topics, Chicago, IL, May 29-June 3, 1994, p754.