{"id":1702,"date":"2012-04-11T05:00:00","date_gmt":"2012-04-11T05:00:00","guid":{"rendered":"https:\/\/stage.idtdna.com\/page\/the-importance-of-melting-temperature-in-molecular-biology-applications"},"modified":"2025-08-07T14:53:45","modified_gmt":"2025-08-07T14:53:45","slug":"the-importance-of-tm-in-molecular-biology-applications","status":"publish","type":"post","link":"https:\/\/stage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/","title":{"rendered":"The importance of melting temperature in molecular biology applications"},"content":{"rendered":"<p>The <a href=\"\/pages\/education\/decoded\/article\/understanding-melting-temperature-(t-sub-m-sub-)\">melting temperature<\/a>&nbsp;of an oligonucleotide duplex, or T<sub>m<\/sub>, is the temperature at which half of the oligonucleotide molecules are single-stranded and half are double-stranded, i.e., the oligonucleotide is 50% annealed to its exact complement. T<sub>m<\/sub> is a critical parameter to consider when designing and performing many molecular biology experiments, including PCR and qPCR.<\/p>\n<h3>Selecting primer melting temperature<\/h3>\n<p>Accurate prediction of T<sub>m<\/sub> identifies duplexes that are likely to form at specific temperatures, allowing you to determine appropriate thermal cycling parameters. During the <a href=\"\/pages\/support\/faqs\/how-do-you-calculate-the-annealing-temperature-for-pcr-\">annealing phase of PCR<\/a>, the reaction temperature needs to be sufficiently low to allow both forward and reverse primers to bind to the template, but not so low as to enable the formation of undesired, non-specific duplexes or intramolecular hairpins, both of which reduce reaction efficiency. Both primers in PCR should be chosen to have a similar T<sub>m<\/sub>.<strong> IDT recommends selecting an annealing temperature 5<\/strong><strong>&ndash;<\/strong><strong>7&deg;C below the lowest primer T<sub>m<\/sub>.<\/strong><\/p>\n<h3>Selecting probe melting temperature<\/h3>\n<p><a href=\"\/pages\/tools\/primerquest\">Designing qPCR assays<\/a> with dual-labeled probes also requires careful coordination of primer T<sub>m<\/sub>. When the reaction temperature is lowered from denaturing to annealing during cycling, the probe needs to anneal first to the target. If the probe binds to the target at the same time or after the primers bind, the polymerase may begin replication of target that does not contain bound probe. As a result, new DNA will be synthesized without associated probe degradation and, therefore, will not be detected as an increase in fluorescence. Such a situation leads to inaccurate data.&nbsp;<strong>For standard qPCR, IDT recommends a probe that has a T<sub>m<\/sub> 5&ndash;10&deg;C higher than the T<sub>m<\/sub> of the primers.<\/strong><\/p>\n<h3>Double-check published T<sub>m<\/sub> data<\/h3>\n<p>It is important to check the T<sub>m<\/sub> of any oligonucleotide sequences used in PCR even when a previously successful primer and probe set is taken directly from a publication. The design of such published sequences may incorporate T<sub>m<\/sub> enhancers such as a minor grove binder or locked nucleic acid bases. These T<sub>m<\/sub> enhancers are not necessary for gene expression analysis; unmodified probe and primer sets that provide reliable, accurate data can be designed for the same targets without the added expense of unnecessary modifications.<\/p>\n<h3>Predicting T<sub>m&nbsp;&nbsp;<\/sub>(Melting Temperature)&nbsp; &nbsp;&nbsp;<\/h3>\n<p>What is an efficient and reliable way to predict T<sub>m<\/sub>? The <a href=\"\/pages\/tools\/oligoanalyzer\">OligoAnalyzer tool<\/a>&nbsp;from IDT&mdash;found in the SciTools applications section of our website\u2015as it is the result of continuing research and innovation. It takes into account the effects of oligonucleotide, cation, dNTP, and salt concentrations, oligonucleotide sequence, and nearest-neighbor interactions. The consideration of all these factors enables accurate prediction of oligonucleotide T<sub>m<\/sub> specific to your reaction conditions [<a href=\"#references\" data-sf-ec-immutable=\"]\">1<\/a>]. For more information on the calculations algorithm used by the OligoAnalyzer tool visit the <a href=\"\/calc\/Analyzer\/Home\/definitions\">tool's definitions page<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The melting temperature&nbsp;of an oligonucleotide duplex, or Tm, is the temperature at which half of the oligonucleotide molecules are single-stranded and half are double-stranded, i.e., the oligonucleotide is 50% annealed to its exact complement. Tm is a critical parameter to consider when designing and performing many molecular biology experiments, including PCR and qPCR. Selecting primer [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"ct_builder_shortcodes":"","ct_template_type":"","ct_parent_template":0,"inline_featured_image":false,"footnotes":""},"class_list":["post-1702","post","type-post","status-publish","format-standard","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.0 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Why is melting temperature important in PCR? | IDT<\/title>\n<meta name=\"description\" content=\"Learn how to predict and select appropriate melting temperatures for oligo hybridization steps, including PCR.\" \/>\n<meta name=\"robots\" content=\"follow\" \/>\n<link rel=\"canonical\" href=\"https:\/\/stage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Why is melting temperature important in PCR? | IDT\" \/>\n<meta property=\"og:description\" content=\"Learn how to predict and select appropriate melting temperatures for oligo hybridization steps, including PCR.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/\" \/>\n<meta property=\"og:site_name\" content=\"IDT\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/idtdna\" \/>\n<meta property=\"article:published_time\" content=\"2012-04-11T05:00:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-08-07T14:53:45+00:00\" \/>\n<meta name=\"author\" content=\"supreme_admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@idtdna\" \/>\n<meta name=\"twitter:site\" content=\"@idtdna\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"supreme_admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/\"},\"author\":{\"name\":\"supreme_admin\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/person\/2d2e0ab8bfe14f62c4d02e858e7302ee\"},\"headline\":\"The importance of melting temperature in molecular biology applications\",\"datePublished\":\"2012-04-11T05:00:00+00:00\",\"dateModified\":\"2025-08-07T14:53:45+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/\"},\"wordCount\":469,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#organization\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/\",\"url\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/\",\"name\":\"Why is melting temperature important in PCR? | IDT\",\"isPartOf\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#website\"},\"datePublished\":\"2012-04-11T05:00:00+00:00\",\"dateModified\":\"2025-08-07T14:53:45+00:00\",\"description\":\"Learn how to predict and select appropriate melting temperatures for oligo hybridization steps, including PCR.\",\"breadcrumb\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/stage.idtdna.com\/page\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"The importance of melting temperature in molecular biology applications\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#website\",\"url\":\"https:\/\/sgstage.idtdna.com\/page\/\",\"name\":\"Integrated DNA Technologies\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/sgstage.idtdna.com\/page\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#organization\",\"name\":\"Integrated DNA Technologies, Inc.\",\"url\":\"https:\/\/sgstage.idtdna.com\/page\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/stage.idtdna.com\/page\/wp-content\/uploads\/2024\/07\/content.svg\",\"contentUrl\":\"https:\/\/stage.idtdna.com\/page\/wp-content\/uploads\/2024\/07\/content.svg\",\"width\":208,\"height\":59,\"caption\":\"Integrated DNA Technologies, Inc.\"},\"image\":{\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/idtdna\",\"https:\/\/x.com\/idtdna\",\"https:\/\/www.instagram.com\/idtdna\/\",\"https:\/\/www.linkedin.com\/company\/integrated-dna-technologies\/\",\"https:\/\/www.youtube.com\/user\/idtdnabio\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/person\/2d2e0ab8bfe14f62c4d02e858e7302ee\",\"name\":\"supreme_admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/b33db2b8496475f7b5b0a33de06c5416bdad923515045a5e9106efc71f7916cc?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/b33db2b8496475f7b5b0a33de06c5416bdad923515045a5e9106efc71f7916cc?s=96&d=mm&r=g\",\"caption\":\"supreme_admin\"},\"sameAs\":[\"https:\/\/stage.idtdna.com\/page\"]}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Why is melting temperature important in PCR? | IDT","description":"Learn how to predict and select appropriate melting temperatures for oligo hybridization steps, including PCR.","robots":{"follow":"follow"},"canonical":"https:\/\/stage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications","og_locale":"en_US","og_type":"article","og_title":"Why is melting temperature important in PCR? | IDT","og_description":"Learn how to predict and select appropriate melting temperatures for oligo hybridization steps, including PCR.","og_url":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/","og_site_name":"IDT","article_publisher":"https:\/\/www.facebook.com\/idtdna","article_published_time":"2012-04-11T05:00:00+00:00","article_modified_time":"2025-08-07T14:53:45+00:00","author":"supreme_admin","twitter_card":"summary_large_image","twitter_creator":"@idtdna","twitter_site":"@idtdna","twitter_misc":{"Written by":"supreme_admin","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#article","isPartOf":{"@id":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/"},"author":{"name":"supreme_admin","@id":"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/person\/2d2e0ab8bfe14f62c4d02e858e7302ee"},"headline":"The importance of melting temperature in molecular biology applications","datePublished":"2012-04-11T05:00:00+00:00","dateModified":"2025-08-07T14:53:45+00:00","mainEntityOfPage":{"@id":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/"},"wordCount":469,"commentCount":0,"publisher":{"@id":"https:\/\/sgstage.idtdna.com\/page\/#organization"},"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/","url":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/","name":"Why is melting temperature important in PCR? | IDT","isPartOf":{"@id":"https:\/\/sgstage.idtdna.com\/page\/#website"},"datePublished":"2012-04-11T05:00:00+00:00","dateModified":"2025-08-07T14:53:45+00:00","description":"Learn how to predict and select appropriate melting temperatures for oligo hybridization steps, including PCR.","breadcrumb":{"@id":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/sgstage.idtdna.com\/page\/support-and-education\/decoded-plus\/the-importance-of-tm-in-molecular-biology-applications\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/stage.idtdna.com\/page\/"},{"@type":"ListItem","position":2,"name":"The importance of melting temperature in molecular biology applications"}]},{"@type":"WebSite","@id":"https:\/\/sgstage.idtdna.com\/page\/#website","url":"https:\/\/sgstage.idtdna.com\/page\/","name":"Integrated DNA Technologies","description":"","publisher":{"@id":"https:\/\/sgstage.idtdna.com\/page\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/sgstage.idtdna.com\/page\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/sgstage.idtdna.com\/page\/#organization","name":"Integrated DNA Technologies, Inc.","url":"https:\/\/sgstage.idtdna.com\/page\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/logo\/image\/","url":"https:\/\/stage.idtdna.com\/page\/wp-content\/uploads\/2024\/07\/content.svg","contentUrl":"https:\/\/stage.idtdna.com\/page\/wp-content\/uploads\/2024\/07\/content.svg","width":208,"height":59,"caption":"Integrated DNA Technologies, Inc."},"image":{"@id":"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/idtdna","https:\/\/x.com\/idtdna","https:\/\/www.instagram.com\/idtdna\/","https:\/\/www.linkedin.com\/company\/integrated-dna-technologies\/","https:\/\/www.youtube.com\/user\/idtdnabio"]},{"@type":"Person","@id":"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/person\/2d2e0ab8bfe14f62c4d02e858e7302ee","name":"supreme_admin","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/sgstage.idtdna.com\/page\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/b33db2b8496475f7b5b0a33de06c5416bdad923515045a5e9106efc71f7916cc?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/b33db2b8496475f7b5b0a33de06c5416bdad923515045a5e9106efc71f7916cc?s=96&d=mm&r=g","caption":"supreme_admin"},"sameAs":["https:\/\/stage.idtdna.com\/page"]}]}},"_links":{"self":[{"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/posts\/1702","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/comments?post=1702"}],"version-history":[{"count":4,"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/posts\/1702\/revisions"}],"predecessor-version":[{"id":4755,"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/posts\/1702\/revisions\/4755"}],"wp:attachment":[{"href":"https:\/\/stage.idtdna.com\/page\/wp-json\/wp\/v2\/media?parent=1702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}