SDS-PAGE and Western blot analysis of cell culture supernatants of B. halodurans BhFDL05S expressing different constructs. (A) SDS-PAGE (15%) analysis of culture supernatants taken from 16 h cultures. The first three lanes each contained crude supernatant (20 μl) and lane 4 (pNWNFFuz) contained concentrated culture supernatant (equivalent to 250 μl of crude supernatant). This was due to relatively low concentrations of the fusion peptide. (B) Western blot analysis of same samples in (A) using Anti-FLAG monoclonal antibodies. (C) Western blot analysis of pNWFliCFFuz (38.2 k Da), pNWNCFFuz (19.8 k Da) and pNWNFFuz (10.5 k Da) with Anti-Enfuvirtide polyclonal antibodies. The amount of sample used for the Western blot was half of that used for the SDS-PAGE gel. Molecular weight markers in kDa are indicated on the left.