{"id":2636,"date":"2026-03-01T01:08:17","date_gmt":"2026-02-28T23:08:17","guid":{"rendered":"https:\/\/science-x.net\/?page_id=2636"},"modified":"2026-03-09T12:40:02","modified_gmt":"2026-03-09T10:40:02","slug":"dna-melting-temperature-tm-calculator","status":"publish","type":"page","link":"https:\/\/science-x.net\/?page_id=2636","title":{"rendered":"DNA Melting Temperature (Tm) Calculator"},"content":{"rendered":"\n<div class=\"eco-tool wp-block-group\" id=\"eco-tool-dna-4e2f9\">\n  <div class=\"eco-tool__header\">\n    <h2 class=\"eco-tool__title\">DNA Melting Temperature (Tm) Calculator<\/h2>\n    <p class=\"eco-tool__lead\">\n      Estimate melting temperature (Tm) and GC content of a short DNA sequence (educational approximation).\n    <\/p>\n  <\/div>\n\n  <form class=\"eco-tool__form\" id=\"eco-dna-form-4e2f9\" novalidate>\n    <div class=\"eco-tool__grid3\">\n\n      <div class=\"eco-tool__field eco-tool__field--wide\">\n        <label class=\"eco-tool__label\" for=\"eco-dna-seq-4e2f9\">DNA sequence (A, T, G, C)<\/label>\n        <textarea class=\"eco-tool__input eco-tool__textarea\" id=\"eco-dna-seq-4e2f9\" rows=\"3\">ATGCGTACGTTAGC<\/textarea>\n        <div class=\"eco-tool__hint\">Enter a short sequence (no spaces or only A\/T\/G\/C).<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-dna-method-4e2f9\">Calculation method<\/label>\n        <select class=\"eco-tool__input\" id=\"eco-dna-method-4e2f9\">\n          <option value=\"wallace\" selected>Wallace rule (short oligos)<\/option>\n          <option value=\"gc\">GC% formula<\/option>\n        <\/select>\n        <div class=\"eco-tool__hint\">Wallace is common for short primers.<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-dna-salt-4e2f9\">Salt correction<\/label>\n        <select class=\"eco-tool__input\" id=\"eco-dna-salt-4e2f9\">\n          <option value=\"off\" selected>Off<\/option>\n          <option value=\"on\">Basic correction<\/option>\n        <\/select>\n        <div class=\"eco-tool__hint\">Adds simple salt adjustment.<\/div>\n      <\/div>\n\n    <\/div>\n\n    <div class=\"eco-tool__actions\">\n      <button type=\"button\" class=\"wp-element-button eco-tool__btn\" id=\"eco-dna-calc-4e2f9\">Calculate<\/button>\n      <button type=\"button\" class=\"wp-element-button eco-tool__btn eco-tool__btn--ghost\" id=\"eco-dna-reset-4e2f9\">Reset<\/button>\n      <div class=\"eco-tool__error\" id=\"eco-dna-error-4e2f9\" aria-live=\"polite\"><\/div>\n    <\/div>\n  <\/form>\n\n  <div class=\"eco-tool__result\" id=\"eco-dna-result-4e2f9\" hidden>\n    <h3 class=\"eco-tool__subtitle\">Result<\/h3>\n\n    <div class=\"eco-tool__cards\">\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Length<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-dna-len-4e2f9\">\u2014<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">GC content<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-dna-gc-4e2f9\">\u2014<\/div>\n      <\/div>\n    <\/div>\n\n    <div class=\"eco-tool__cards\">\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Melting temperature (Tm)<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-dna-tm-4e2f9\">\u2014<\/div>\n        <div class=\"eco-tool__metric-sub\" id=\"eco-dna-note-4e2f9\"><\/div>\n      <\/div>\n    <\/div>\n\n    <p class=\"eco-tool__note\">\n      Simplified model for educational purposes. Real lab conditions require precise thermodynamic calculations.\n    <\/p>\n  <\/div>\n<\/div>\n\n<style>\n.eco-tool{border:1px solid rgba(0,0,0,.12);border-radius:12px;padding:16px}\n.eco-tool__grid3{display:grid;grid-template-columns:1fr;gap:16px}\n@media(min-width:860px){.eco-tool__grid3{grid-template-columns:1fr 1fr 1fr}}\n.eco-tool__field{display:flex;flex-direction:column;gap:6px}\n.eco-tool__field--wide{grid-column:1\/-1}\n.eco-tool__label{font-weight:600}\n.eco-tool__input{width:100%;height:44px;padding:0 12px;border:1px solid rgba(0,0,0,.2);border-radius:10px;background:#fff;box-sizing:border-box;font:inherit}\n.eco-tool__textarea{height:auto;padding:10px 12px;resize:vertical}\n.eco-tool__actions{display:flex;gap:10px;margin-top:16px;align-items:center;flex-wrap:wrap}\n.eco-tool__btn{padding:10px 22px}\n.eco-tool__btn--ghost{background:transparent!important;border:1px solid rgba(0,0,0,.2)!important}\n.eco-tool__btn--ghost:hover,.eco-tool__btn--ghost:focus{background:rgba(0,0,0,.06)!important;border-color:rgba(0,0,0,.35)!important}\n.eco-tool__error{min-height:1.2em;font-weight:600;flex:1 1 240px}\n.eco-tool__cards{display:grid;gap:10px;margin-top:16px}\n@media(min-width:860px){.eco-tool__cards{grid-template-columns:1fr 1fr}}\n.eco-tool__card{border:1px solid rgba(0,0,0,.12);border-radius:12px;padding:12px}\n.eco-tool__metric-value{font-size:1.6em;font-weight:800;margin-top:6px}\n.eco-tool__metric-sub{opacity:.85;margin-top:6px}\n<\/style>\n\n<script>\n(function(){\n  const S=\"4e2f9\";\n  const el=id=>document.getElementById(id+\"-\"+S);\n\n  const seqEl=el(\"eco-dna-seq\");\n  const methodEl=el(\"eco-dna-method\");\n  const saltEl=el(\"eco-dna-salt\");\n\n  const calc=el(\"eco-dna-calc\");\n  const reset=el(\"eco-dna-reset\");\n  const err=el(\"eco-dna-error\");\n\n  const res=el(\"eco-dna-result\");\n  const lenOut=el(\"eco-dna-len\");\n  const gcOut=el(\"eco-dna-gc\");\n  const tmOut=el(\"eco-dna-tm\");\n  const noteOut=el(\"eco-dna-note\");\n\n  function setError(m){ err.textContent=m||\"\"; }\n\n  calc.addEventListener(\"click\",function(){\n    setError(\"\");\n\n    let seq=seqEl.value.toUpperCase().replace(\/[^ATGC]\/g,\"\");\n    if(seq.length===0){\n      setError(\"Please enter a valid DNA sequence (A\/T\/G\/C only).\");\n      res.hidden=true;\n      return;\n    }\n\n    const len=seq.length;\n    const A=(seq.match(\/A\/g)||[]).length;\n    const T=(seq.match(\/T\/g)||[]).length;\n    const G=(seq.match(\/G\/g)||[]).length;\n    const C=(seq.match(\/C\/g)||[]).length;\n\n    const gc=(G+C)\/len*100;\n\n    let Tm;\n\n    if(methodEl.value===\"wallace\"){\n      Tm = 2*(A+T) + 4*(G+C);\n    } else {\n      Tm = 64.9 + 41*((G+C-16.4)\/len);\n    }\n\n    if(saltEl.value===\"on\"){\n      Tm += 5;\n    }\n\n    lenOut.textContent = len.toLocaleString() + \" bp\";\n    gcOut.textContent = gc.toLocaleString() + \" %\";\n    tmOut.textContent = Tm.toLocaleString() + \" \u00b0C\";\n\n    noteOut.textContent =\n      methodEl.value===\"wallace\"\n      ? \"Wallace rule: 2\u00b0C per A\/T and 4\u00b0C per G\/C.\"\n      : \"GC-based approximation for longer sequences.\";\n\n    res.hidden=false;\n  });\n\n  reset.addEventListener(\"click\",function(){\n    setError(\"\");\n    seqEl.value=\"ATGCGTACGTTAGC\";\n    methodEl.value=\"wallace\";\n    saltEl.value=\"off\";\n    res.hidden=true;\n  });\n\n})();\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>DNA Melting Temperature (Tm) Calculator Estimate melting temperature (Tm) and GC content of a short DNA sequence (educational approximation). DNA sequence (A, T, G, C) ATGCGTACGTTAGC Enter a short sequence&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":2571,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"_links":{"self":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2636"}],"collection":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2636"}],"version-history":[{"count":2,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2636\/revisions"}],"predecessor-version":[{"id":2682,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2636\/revisions\/2682"}],"up":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2571"}],"wp:attachment":[{"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2636"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}