Geromanos S, Philip J, Freckleton G, Tempst P
Protein Center, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Rapid Commun Mass Spectrom. 1998;12(9):551-6. doi: 10.1002/(SICI)1097-0231(19980515)12:9<551::AID-RCM198>3.0.CO;2-Y.
Nanoelectrospray ('nanoES') tandem mass spectrometry of complex peptide mixtures has become a certified, mostly reliable technique for the identification of proteins. The typical low flow rates of nanoES, the extended analysis times for small samples, high ion transmission and its overall ease-of-use provide important practical advantages for polypeptide covalent microanalysis. We have constructed a modified nanoES ion source that is highly durable and user-friendly, and potentially allows for full auto-sampling operation. The inJection adaptable Fine Ionization Source ('JaFIS') can be operated at flow rates of 10-100 nL per minute and with sensitivities in the 25 femtomoles peptide per microliter range. The ion spray needles usually last for days, allowing for standards and multiple samples to be analyzed consecutively under similar conditions. In this configuration, quality controlled needles can also be saved and reused, providing for more consistent and reproducible day-to-day operating conditions, JaFIS-ES also permits sample recovery should any failure occur during analysis.
