This 250mL container of gelatin from cold water fish skin is used as a blocking agent in immunochemistry. It has a concentration of 45% in H20. It contains 0.15% propyl p-hydroxybenzoate and 0.2% methyl-p-hydroxybenzoate as a preservative. It is also known as gelaine or Teleostean gelatin. Material: Gelatin From Cold Water Fish Skin. Concentration: 45% In H20. Molecular Weight: Approximately 60kDa. Form: Liquid. Solubility: Water Soluble. Storage Temperature: 2 To 8°C. Quantity: 250mL. Sigma-Aldrich® #: G7765-250ML.