About DNARev

Why It Exists

The reverse complement is one of the most common small jobs in molecular biology, and the classic tool for it, the Reverse Complement page of the Sequence Manipulation Suite (SMS) by Paul Stothard, has been trusted for over two decades. DNARev keeps its exact results and adds a faster, accessible interface, multi-FASTA support and RNA.

Method and Accuracy

• With DNA selected and Each record separately off, DNARev runs the same steps as SMS: remove the first FASTA header, keep only G, A, T, C and N, then reverse and/or complement. DNARev shows sequences in upper case, so the bases match SMS but lower-case input comes out in capitals. FASTA header lines are left as typed.
• Opened files are limited to .txt, FASTA, FASTQ, GenBank and EMBL, up to 10 MB. FASTQ, GenBank and EMBL records are converted to FASTA first; anything else, including binary files, is refused.
• Every release is tested against the original SMS code: 500 random inputs in each of the three modes must match character for character.
• RNA and Each record separately are DNARev additions. They are off by default and clearly labelled, so the default output never changes.
• Anything removed from your input (spaces, numbers, ambiguity codes, extra headers) is reported in a note under the result.

Privacy

• Your sequences never leave your device. All conversion happens in your browser, and nothing is sent to a server or stored. Files you open are read by your browser, not uploaded. The Paste button reads your clipboard only when you press it.
• There are no cookies, analytics, ads or third-party scripts.
• The site remembers four display choices (theme, line width, base colouring and the sequence options) in your browser’s local storage. Clearing your site data removes them.
• Like any web server, ours keeps standard access logs (IP address, time, page requested) for security and troubleshooting.

Accessibility

DNARev is built to WCAG 2.2 AA. It is tested with automated accessibility checks in light and dark themes at five screen widths, works with a keyboard alone, supports Windows High Contrast and reduced motion, and announces results and actions to screen readers.

Credits

• Original algorithm: Sequence Manipulation Suite by Paul Stothard (2000).
• Typefaces: Manrope and JetBrains Mono, both under the SIL Open Font License.