Equation 5 estimates the probability that a fragment will be correct after a cycle of MutS filtering, P(F 0 ), by applying a MutS selectivity factor (M ) to adjust the relative amounts of mismatch containing duplexes (I, H ) while accounting for the total fraction of correct strands in the re-hybridized duplexes. The probability of obtaining an error free assembly product, P(A), is then given by Equation 6 .