Calculators that run in your browser
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Melting temperature (Tm)
Nearest-neighbour thermodynamics (SantaLucia 1998 unified parameters) with salt correction (Owczarzy 2004). Valid for DNA duplexes; the value shown is for the sequence annealing to its perfect complement.
Reverse complement & translate
Handles IUPAC ambiguity codes. Translation uses the standard genetic code, frame 1 of the sequence as entered.
Bio calculator — OD, nmol, µg, resuspension
Extinction coefficient is computed by the nearest-neighbour method with hyperchromicity correction, so the conversion is sequence-specific rather than a generic 33 µg/OD rule of thumb.
Self-dimer, cross-dimer and hairpin screen
A complementarity screen, not a full thermodynamic folding prediction: it reports the longest and the most 3′-proximal complementary stretches, which is what usually causes primer-dimer artefacts. Treat it as a red flag detector, not as a Tm for the secondary structure.
Dye–quencher pair checker
Checks whether the dye emission falls inside the quencher's published absorbance range, and whether the dye clashes with a common detection channel. The numbers used are shown with the answer so you can check the reasoning rather than trust a verdict.