When preparing PCR samples in plates, strips and single tubes, PCR solutions must be kept cool as warming may result in unspecific PCR products. Our new IsoFreeze PCR Racks prevent sample damage caused by premature warming. Using IsoFreeze PCR Racks provides considerable advantages: Once pre-chilled, the rack can maintain the PCR sample temperature at approximately 4 degrees C for up to 3 hours in ambient conditions. If sample temperatures exceed 7 degrees C, the rack visibly changes color from purple to pink to alert users. The racks are sold in a pack of two so that a warm rack can be conveniently exchanged for a chilled rack during prolonged use.