Artifacts associated with 2-mercaptoethanol upon high resolution two-dimensional electrophoresis.

The presence of 2-mercaptoethanol in the protein denaturing solution used to prepare samples for high resolution two-dimensional electrophoresis can result in artifacts when the two-dimensional patterns are detected by silver staining. These are (i) spots of discrete isoelectric point and electrophoretic mobility, (ii) horizontal bands of the same electrophoretic mobility as the spots (corresponding predominantly to molecular weights of 54,000 and 68,000), and (iii) vertical streaks of variable length and intensity. Although the nature and source of artifacts have not been positively identified the evidence suggests that they are probably not inherent in the 2-mercaptoethanol itself but rather released by the latter from some component common to both the first- and second-dimension constituents of the electrophoretic system.