Thermal cycler PCR, also known as gene amplification instrument, is an instrument that uses temperature to denature DNA, and replicates single strands into double strands under the action of polymerase, thereby achieving the purpose of gene replication. PCR machines have a wide range of applications and are involved in almost all life science fields.

The hot cover is on the upper part of PCR machine. After close the PCR instrument, the part that is close to the PCR tube cap is hot cover. Current thermal cyclers are generally equipped with a hot cover, which has a default setting in temperature. Usually it should be above 100°C, but if this setting is changed, or if the hot cover is not used at all when running the program, sample loss will occur.

The temperature of hot cover is generally set to 105°C, so that the temperature at the top of the sample tube reaches about 105°C, and the evaporated reaction solution will not agglomerate on the tube cover to change the reaction volume, so the users do not need to add paraffin oil to the reaction tube, which directly reduces the trouble of subsequent reactions.

If it is a rotary pressurized hot cover, special care should be taken, because there is no obvious prompt when the pressure is reached, and the user needs to rotate the hot cover to the appropriate position according to experience. If it is too loose, the hot cover will not fully contact the reaction tube and the results will be affected. If it is too tight, it will cause deformation of the reaction tube and possibly even mechanical failure of the hot cover.