Two-dimensional protein analysis at high resolution on a microscale.

Proteins from small amounts of biological material are separated at high resolution by micro two-dimensional gel electrophoresis. Under nonequilibrium conditions, proteins are focused in 10-microliters capillaries and separated on ultrathin slab gels. Our device allows simultaneous focusing of up to 10 samples which can be processed in the second dimension on a single gel. Several hundred protein spots from less than a total of 300 ng of protein are resolved on an area the size of a postage stamp. A single spot containing less than 10 pg of protein or 1 cpm can be detected by silver staining or autoradiography, respectively. Our system allows inexpensive, simultaneous, rapid analysis of proteins when only a limited amount of biological material is available for investigation. A detailed description of the equipment, the methods, and the characteristics of this microanalysis are presented.