Direct vertical electroelution of protein from a PhastSystem band for massspectrometric identification at the level of a few picomoles

An electroelution apparatus prototype of a new design was constructed. In t hat design, the electric field passes vertically through the protein band l ocated on a horizontal (PhastSystem) minigel polymerized on a net of Gel-Fi x (Serva). A simple, home-made apparatus allows for electroelution of prote in bands at the level of a few picomoles and their identification, after co ncentration, by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The technique is applicable to one-dimensional (I-D) or two-dimensional (2-D) gels of any size, but has been exemplified only by ap plication to I-D minigels to demonstrate the lower limits of protein load o f the method. When in the course of further development of the prototype it will be combined with a modification to two dimensions of the electroeluti on mechanism under computer control of the high-performance gel electrophor esis apparatus**** (formerly of LabIntelligence), the new design appears un iquely qualified for an automated spot elution from 2-D gels under avoidanc e of gel sectioning.