Integrated system for high-throughput protein identification using a microfabricated device coupled to capillary electrophoresis/nanoelectrospray mass spectrometry
Jj. Li et al., Integrated system for high-throughput protein identification using a microfabricated device coupled to capillary electrophoresis/nanoelectrospray mass spectrometry, PROTEOMICS, 1(8), 2001, pp. 975-986
An integrated microsystem providing rapid analyses of trace-level tryptic d
igests for proteomics application is presented. This modular microsystem in
cludes an autosampler and a microfabricated device comprising a sample intr
oduction port and an array of separation channels together with a low dead-
volume facilitating the interface to nanoelectrospray mass spectrometry. Se
quential injection and separation of peptide standards and tryptic digests
was achieved with a throughput of up to 30 samples per hour with less than
3% sample carryover. Replicate injections of peptide mixtures indicated tha
t reproducibility of migration time was typically better than 2.3% relative
standard deviation (RSD) whereas RSD values of 3.7-11.8% were observed on
peak height. Mass spectral detection of submicromolar protein digests (< 7
femtomoles/injection) was achieved using a quadrupole/time of flight instru
ment in less than 2 min/per sample with peak widths of 1.8-7.0 s. The analy
tical potential of this integrated device for the identification of gel iso
lated proteins from Neisseria meningitidis immunotype L3 has been demonstra
ted using both peptide mass-fingerprint database searching and on-line tand
em mass spectrometry.