An attempt was made to conceive a simple, rapid and effective method to extract total plant proteins from cotton leaf samples for proteomic analysis; particularly SDS PAGE. The protocol combines TCA/acetone precipitation, methanol washes and phenol extraction as reported by Wang et al., (2006) with few modifications to separate the proteins from several interfering compounds like lipids, polysaccharides, phenolics, terpenes, pigments, organic acids, nucleic acids, free ions, proteolytic and oxidative enzymes; and precipitate high-quality protein from a very low amount of starting material. The key components of this protocol were water soluble PVP and DTT (those prevent oxidation of phenolic compounds); and PMSF which acted as a protease inhibitor and the key step in this protocol was the phenol extraction step. The overall quality of the protein was good with less vertical streaking and smearing in the SDS PAGE gel and the average protein yield obtained was approximately 510 g/g fresh weight of cotton leaf.

Download this article as