The Mycoplasma gallisepticum strains [wild-type S6 (208) and a vaccine-type F-K810] grown in Frey´s and Hayflick´s media were analyzed by SDS-PAGE. No visual changes in the protein profiles of these strains were observed regardless of the media composition used, although the polyacrylamide gel electrophoretograms showed minor differences do exist when densitometer traces of the gel are compared. Both strains were easily differentiated on SDS-PAGE analysis by a peptide band p75, that is specific for MG F-K810 strain, used as vaccine.
