by K Chico, Jessica Piczon

Polymerase chain reaction (PCR) has become an important tool in many fields, including molecular diagnostics. Increasingly, laboratories use 96- and 384-well plates instead of individual tubes since they simplify and accelerate the handling of many samples at once, allowing for higher throughput. PCR plate seals are used to protect the samples used against contamination and evaporation.

There are three main platforms to seal PCR and rt-PCR plates, including heat sealing, adhesive seals, and cap strips. Regarding plate choice, it is important to always use a PCR plate, and not tissue culture plates, flat bottomed, or round plates. White PCR plates are often the go-to choice because of their inherently low autofluorescence, which can improve quantification. Plates of a different color may increase the variation of fluorescence between wells and significantly influence the PCR results. For this reason among others, calibration plates are frequently employed as an additional failsafe to ensure reproducibility.

If special chemicals are used such as acids, bases, or organic solvents, the compatibility of the seal with the substance must be assessed. Below are a few considerations on choosing the correct seal for your PCR application.

Below are instructions for correctly applying an adhesive seal to a PCR plate.