PCR plate sealing mats are reusable, economical, and convenient for sealing PCR plates for oil-free thermal cycling reactions. The sealing mats are for 96-well plates and have an array of 96 bumps to help orient the rubber mat on the PCR plate. The mats are autoclavable and may be cleaned with bleach for reuse. UV treatment is not recommended. The mats may be used up to 50 times.