The IsoFreeze polymerase chain reaction (PCR) rack from Sarstedt, Newton, NC, ensures consistently cooled PCR samples. Premature warming of PCR samples during preparation can result in nonspecific PCR products. The rack is available in a 96-sample format for 0.2 ml and 0.3 ml PCR tubes, strips, and plates. Once prechilled, the rack can maintain the PCR sample temperature at approximately 4°C for up to 3 hours in ambient conditions. If sample temperatures exceed 7°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. For more information, visit Sarstedt.