Direct immunodetection of surface adsorbed proteins

Abstract

A modification of standard immunoblotting techniques gives rise to a novel method of imaging surface associated proteins without removing them from their original arrangement on the surface. The original proteins and subsequent antibody probe reactions are performed directly on the surface. The substrate is adsorbed into the nitrocellulose support which, in semi-dry contact, reacts only in the regions in which the target protein is antigenically present. The sensitivity of the method is comparable to other immunological techniques and diffusion of the resulting images is negligible resulting in reproducible reblots from the same surface with high lateral resolution. The method can be applied to a wide variety of reasonably flat surfaces. It demonstrates two dimensional protein patterns as a function of varying surface characteristics as well as differing protein detectabilities in their purified form as opposed to the same molecule as a plasma protein component adsorbed onto a surface. The method promises to be a useful tool in circumstances where surface bound proteins are not completely removable from surfaces or are lost in commonly used extraction or analytical techniques.