Plasmid Map Viewer & Restriction Sites
Interactive circular vector maps with feature arcs and single-cutter restriction enzyme site annotation.
How it works
Circular maps are drawn by converting sequence coordinates to polar angles, placing feature arcs for coding sequences, promoters, origins and resistance markers. Restriction sites are found by scanning for each enzyme’s recognition sequence, with single cutters highlighted because they are the useful ones for linearising or diagnostic digests.
Frequently asked questions
How do I find unique restriction sites in a plasmid?
Scan the full circular sequence for every enzyme recognition site and count occurrences. Enzymes cutting exactly once are the useful ones: they linearise the plasmid cleanly, and a pair of them defines a fragment of predictable size for diagnostic digests. Also check that a candidate site does not fall inside a feature you need intact, such as the resistance marker or origin.
What is a diagnostic restriction digest?
A diagnostic digest cuts a plasmid with chosen enzymes to produce a fragment pattern that confirms the construct is correct. A successful clone yields fragment sizes that differ predictably from the empty vector or from an insert in the wrong orientation, so a single gel distinguishes them. It is a quick check before committing a clone to sequencing.