Quick sequence utilities — all calculations run instantly in your browser
Reverse complement of any DNA sequence • Primer analysis: length, GC%, melting temperature • Coverage estimator: expected sequencing depth from read count and length
Reverse Complement
Result will appear here
Length
—
GC content
—
Primer Analysis i
Length
—
GC content
—
Tm (Wallace rule, ≤ 13 nt)
—
Tm (salt-adjusted, > 13 nt)
—
Tm estimates assume 50 mM Na⁺, 250 nM primer. For precise values use a dedicated tool.
Coverage Depth Estimator
Total bases sequenced
—
Expected coverage
—
Background reading and sources
Tm — Wallace rule (≤ 13 nt)
Formula: Tm = 2(A+T) + 4(G+C)
Thein, S.L. & Wallace, R.B. (1986). The use of synthetic oligonucleotides as specific hybridization probes in the diagnosis of genetic disorders. In: Davies K.E. (ed.), Human Genetic Diseases: A Practical Approach. IRL Press, Oxford. pp. 33–50.
doi:10.1093/oso/9780199633098.003.0002
Tm — salt-adjusted formula (> 13 nt)
Formula: Tm = 81.5 + 16.6 · log₁₀([Na⁺]) + 0.41 · (%GC) − 675/n
Rychlik, W., Spencer, W.J. & Rhoads, R.E. (1990). Optimization of the annealing temperature for DNA amplification in vitro. Nucleic Acids Research, 18(21), 6409–6412.
doi:10.1093/nar/18.21.6409
GC content warnings (< 40%, > 65%), length warnings (< 18 nt, > 30 nt)
Dieffenbach, C.W., Lowe, T.M.J. & Dveksler, G.S. (1993). General concepts for PCR primer design. PCR Methods and Applications, 3, S30–S37.
doi:10.1101/gr.3.3.S30
