The crosslinking reaction between Fbg αC (233 – 425) WT and variants (Fbg αC Q328P, Fbg αC Q328PQ366N, and Fbg αC 389Stop) and MDC was initiated by adding 100 nM proteolytically or non-proteolytically activated FXIII-A (FXIII-A*/FXIII-A°). The positive control used was MDC crosslinked into N, N-dimethylated β-casein. The quantification of the gels was performed as described in the methods section. The curves represent one phase exponential association fits of the data as a function of time. Data were reported as mean ± SD (N=3). The gels for the MDC incorporation and the quantification curves include Fbg αC (233 – 425) WT (A and B), Fbg αC (233 – 425) Q328P (C and D), Fbg αC (233 – 425) Q328PQ366N (E and F), and Fbg αC (233 – 388) 389Stop (G and H). t-tests analysis showed that activity differences between FXIII-A* and FXIII-A° are significant (***P < 0.001) for all substrates except Fbg αC (233 – 388) 389Stop.