Figure 1.

Optimization of protein solubilization and recovery in urea-containing solution. 1D SDS-PAGE of proteins prepared by direct extraction (a, e), or by extraction, precipitation and re-solubilization (b–d). Proteins were prepared by a) direct extraction in the urea-containing solution. For other extraction/precipitation/re-solubilization, proteins were b) extracted in 1% Triton X100-containing buffer, c) in RIPA buffer, d) in 1% SDS, followed by precipitation with 20% acetic acid and 40% methanol, and solubilization in the urea-containing solution. e) As a control of maximal extraction, proteins were extracted directly with 1% SDS. Separated proteins were stained with Coomassie Briliant Blue R-250.