A generalized theory for gel controlling dead-end filtration is derived here from first principle by taking into account the change of retentate concentration with time of operation. The conventional notion that feed concentration is unchanged in the absence of external turbulence is not realistic. The present theoretical development challenges the classical theory that predicts the performance of dead end filtration considering constant retentate concentration. However, there are certain situations, especially in the cases of low retentate volume, the classical theory fails completely. The domain of applicability of the present generalized model is also identified. The theoretical development based on the developing boundary layer analysis is presented in this study. The relative comparison of the classical theory with the present model is also illustrated. (C) 2012 Elsevier B.V. All rights reserved.