Time-course of pyrrole modification of fibrinogen standard. DHM was added to a bovine fibrinogen standard at a 10 molar excess. Aliquots were taken between 0 and 120 min post pyrrole addition and analysed by 1-D SDS-PAGE. Protein samples were mixed with reducing sample buffer and analysed on a 7.5% (w/v) gel. The gel was stained with Coomassie brilliant blue. From 30 min onwards the density of the fibrinogen bands, in particular the α-chain, appear to be diminished after reaction with the pyrrole. Key: - = control reaction mixture complete apart from DHM; + = reaction mixture containing DHM.