The inventive technology relates to methods and apparatus for reducing proteincontent in sperm cell extenders and may include one or more of the following features:techniques for reducing protein content in a sperm cell extender； techniquesfor reducing protein content in a cryoprotectant-containing B fraction of asperm cell extender； techniques for preparing sperm cell extenders that do notrequire clarification； techniques for preparing low density gradient spermcell extenders suitable for centrifugation； techniques for reducing proteincontent between individual steps in preparing a sperm cell extender, and techniquesfor establishing novel values of reduced protein content in sperm cell extenders.
