One-dimensional protein analysis of an HT29 human colon adenocarcinoma cell

A single HT29 human colon adenocarcinoma cell was introduced into a fused-s ilica capillary and lysed, and the protein content was fluorescently labele d with the fluorogenic reagent 3-(2-furoyl)quinoline-2-carboxaldehyde. The labeled proteins were separated by capillary electrophoresis in a submicell ar buffer and detected by laser-induced fluorescence in a postcolumn sheath -now cuvette. Several dozen components were resolved. A number of experimen ts were done to verify that these components were proteins. Most components of the single-cell electropherogram had the same mobility as components pr esent in the 30-100 kDa fraction of a protein extract prepared from the cel l culture. One component was identified as a similar to 100 kDa protein by co-injecting the sample with purified protein obtained from an SDS-PAGE gel . Protein expression varied significantly between cells, but the average ex pression was consistent with that observed from a protein extract prepared from 10(6) cells.