Does it search the reverse strand?

No — only the three forward frames. To search the reverse strand, reverse-complement the sequence first with the reverse complement tool and run it again.

How is ORF length measured?

In nucleotides from the A of the ATG through the last base of the stop codon, so it includes the stop. The protein length excludes the stop.

ORF finder

Find open reading frames (ATG to stop) in the three forward frames of a DNA sequence and translate each to protein, with frame, position and length.

How it works

Formula

In each of the three forward frames, scan codons for a start (ATG) and read until the next in-frame stop (TAA, TAG or TGA). The protein is the translation from the start codon up to, but not including, the stop.

Worked example

ATG GCA AAA TTT TAA translates to M-A-K-F then a stop: one 15 nt ORF in frame 1 encoding the 4-residue protein MAKF.

When to use it

To locate candidate coding regions in a cloned insert, PCR product or short contig, or to confirm an ORF is intact and in frame before expression.

Sensible defaults

The default sequence contains a 33 nt ORF (protein MAKFGPTDEF). The minimum length defaults to 30 nt (10 codons); lower it to catch very short ORFs, raise it to focus on likely genuine genes.

FAQ

Does it search the reverse strand?: No — only the three forward frames. To search the reverse strand, reverse-complement the sequence first with the reverse complement tool and run it again.
How is ORF length measured?: In nucleotides from the A of the ATG through the last base of the stop codon, so it includes the stop. The protein length excludes the stop.