热启动聚合酶链式反应（英语：Hot start PCR）是一种改良的聚合酶链式反应方法，主要用来避免操作过程中产生非特异性串行的扩增。将DNA聚合酶与其他反应物隔绝，或是使用在高热状况下才会活化的聚合酶，避免在未达到设置温度前就开始反应。

热启动PCR有几种方式：

Hot start PCR is a modified form of Polymerase chain reaction (PCR) which avoids a non-specific amplification of DNA by inactivating the taq polymerase at lower temperatures. The polymerase chain reaction (PCR) is a technology in molecular biology used to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. In Hot start PCR specific antibodies are used to block the Taq-polymerase at lower temperature. An initial step at 95℃ is required for denaturing the antibodies linked to the active center of the enzyme. The anti-Taq antibodies reduce the Taq polymerase activity below 72℃, the optimal temperature at which the enzyme extends the primers. When the specific antibodies detaches from Taq-polymerase the amplification proceeds with greater specificity.