Problems encountered in identification of penicillin binding proteins with pneumococcus used as an example

: Whole cells or isolated membranes of Streptococcus pneumoniae were treated with labelled benzyl penicillin and the penicillin binding proteins (PBPs) were visualized by fluorography after SDS-PAGE electrophoresis. The PBP profiles obtained for strains sensitive and resistant to penicillin strongly differed depending not only on the concentrations of acrylamide and bis-acrylamide used in the separating gel but also on the batch used (different manufacturers). The latter was also true for sodium dodecyl sulfate.