SDS-PAGE and western blot analysis of all synthetic CipA variants. Supernatants of CipA-expressing recombinant C. acetobutylicum strains were mixed with Avicel (crystalline cellulose) and proteins harbouring a carbohydrate binding module (CBM), including the CipA variants, were pulled down. (a) SDS-PAGE analysis and Simply blue staining (Invitrogen) of the Avicel bound culture supernatants of the first six CipA variants (CipA2-CipA7) (b) Western blot analysis of the Avicel bound CipA scaffold variants (CipA2-CipA7) using ANTI-FLAG M2 monoclonal antibody-horseradish peroxidise conjugate (Sigma). Samples were concentrated 100 fold. (c) Western blot analysis of the Avicel bound CipA scaffold variants (CipA6-CipA full length) using the same antibody. These samples were concentrated 150 fold. Expected molecular masses are indicated by red arrows. M, ColorPlus Prestained Protein Ladder (10–230 kDa; New England Biolabs), Flag, N-Flag-Bap control protein (50 kDa, 50 ng/lane; Sigma).