Gel electrophoresis combs form Genesee Scientific are built to a high standard of quality and durability. The teeth are precision machined from tough acrylci and the spine is made from thick PTFE to offer better heat resistant stiffness. While the recommendation is to allow the freshly dissolved agarose to cool, these combs and gel trays will withstand abuses that will damage inferior injection molded equipment. Every comb is labled with the number of teeth and tooth thickness - avoid counting teeth to find the right comb!