The reproducibility of a chromatographic column has a critical impact on the long-term reliability and robustness of an analytical method, and its reproducibility lies completely outside the user's control. With exceptional batch-to-batch and column-to-column reproducibility, Waters well-established particle and column manufacturing process control provides confidence in the long-term reliability of your analytical method. XBridge BEH300 C4, 3.5um Method Validation Kit includes three batches of chromatographic media [derived from different base particles] to judge the quality, reliability, and consistency of your chromatographic method. Each batch of selected XBridge BEH300 C18, 3.5um chemistry is specifically QC tested with a mixture of carefully selected protein standards to help ensure consistent performance.