StyD4I (CCNGG) has 4 possible recognition sequences. These include two, CCAGG and CCTGG can be blocked by dcm methylation CCWGG (W=A or T). The other two recognition sites CCCGG and CCGGG are not blocked by dcm methylation. Note dcm methylation can be removed or avoided by using the NEB dam-/dcm- Competent E. coli strain (C2925).