Frequently Asked Questions of thermal Cycler

• Why are the bands amplified on different models of PCR instruments different in brightness?

Answer: Different PCR machines have different optimized heating and cooling strategies. Therefore, when transferring the PCR step parameters used on this type of CR machine to another type of PCR machine, it is necessary to perform experimental optimization.

• Can my samples be kept in the PCR machine at low temperature after the PCR experiment is over?

Answer: It is best not to. It is recommended that the samples should be taken out of the PCR machine in time after the program runs. When storing at low temperature, try to set a higher temperature, which can prolong the service life of the instrument.

• What is the difference between analog tube and sample stage temperature control mode?

If the sample stage temperature control mode is adopted, when the sample stage is raised and lowered to the target temperature, it will take a long time for the sample in the sample tube to reach the target temperature due to the heat transfer delay. Therefore, when the step time is less than 30s, it is best to use Simulation control. If you want to use the sample stage temperature control mode, it is best to double the step time.

• Droplets appear on the wall of the reaction tube after the reaction?

Possible reason 1: Before the program is running, the heating function of the hot lid is not turned on. Method: Turn on the heating function of the hot lid.

Possible reason 2: After the reaction is over, it is stored at a low temperature for too long.

Method: After the end of the operation, the hot lid will automatically close, so condensation will occur, which will not affect the results of the experiment. Place the reaction tube on the centrifuge and centrifuge briefly to make the droplets return to the bottom of the tube.

• For the microplate used, the reaction solution evaporates significantly after the reaction?

Methods: (1) Ensure that the quality of the microtiter plate used is very good. Before the reaction, it must be tightly sealed. (2) Ensure that the lid is tightly closed, and increase the temperature of the lid appropriately. (3) Increase the reaction volume.

When using a PCR tube, some of the reaction solution in the PCR tube evaporates significantly after the reaction?

Method: (1) Ensure that the PCR tube used is of high quality. (2) Place four identical empty PCR tubes on the four corners of the sample table respectively, so that the pressure of the heat cover on each PCR tube can be ensured evenly.

Maintenance and precautions of gene thermal cycler

• Cleaning the sample cell

First open the lid, then add 95% ethanol or 10% cleaning solution to the sample cell, soak for 5 minutes, then clean the contaminated wells, use a micropipette to aspirate the liquid, and use a cotton swab to absorb the remaining liquid. Turn on the PCR machine, set the holding temperature to 50°C to run the PCR program, and volatilize and remove the residual liquid, which usually only takes about 5-10 minutes.

• Cleaning of the hot cover

For a fluorescent quantitative PCR instrument, if fluorescent pollution occurs and the sample cell is not the source of this pollution, or when the tightness of the thermal cover is affected by pollution or residues, the bottom surface of the cushion cover needs to be cleaned with compressed air or pure water to make the sample The hole of the pool is clean, and no dirt blocking the light path is guaranteed.

• Cleaning the outer surface of the instrument

Cleaning the outer surface of the instrument can remove dust and grease, but it cannot achieve the effect of disinfection. It is best to choose a non-corrosive cleaning agent to clean the outer surface of the PCR instrument.

• Replace the fuse

First turn off the PCR machine, pull out the plug, open the fuse box next to the power socket, replace the spare fuse, and observe whether it returns to normal.