Protein purification from polyacrylamide gels by sonication extraction.

A protein purification procedure using sonication extraction from polyacrylamide gels (PAGE), which involves identification of a particular protein band and its excision, homogenization, sonication, and subsequent passage through a Sephadex G-25 minicolumn, is reported. Our results show a high degree of recovery regardless of the nature of the protein (soluble or membrane bound) or the characteristics of the gel (SDS-PAGE, native gels, or Tricine-SDS-PAGE). The percentage of recovery was dependent on the protein concentration applied in the gel. This technique is fast, gives high yield, provides good resolution, and can be used without any specialized equipment. The method was tested with a wide variety of membranes and soluble proteins and was found to give good results and to be applicable to different studies. The amino acid sequence of one of the purified proteins (Rf 0.45 stallion ejaculated sperm protein) was determined successfully.