Gelatin, Skin

Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular weights, present in collagen. The proteins are extracted by boiling skin, tendons, ligaments, bones, etc. in water. Type A gelatin is derived from acid-cured tissue and Type B gelatin is derived from lime-cured tissue. The charge on a gelatin molecule and its isoelectric point are primarily due to the carboxyl amino and guanidino groups on the side chains. Type A gelatin has 78-80 millimoles of free carboxyl groups per 100g of protein and a pI of 7.0-9.0; type B has 100-115 millimoles of free carboxyl groups per 100g of protein and a pI of 4.7-5.2. The pH of a 1.5% solution at 25 degrees C is 3.8-5.5 for Type A and 5.0-7.5 for Type B. Applications using gelatin include coating cell culture plates to improve cell attachment for a variety of cell types, addition to PCR to help stabilize Taq DNA polymerase, and use as a blocking reagent in Western Blot, ELISA, and Immunohistochemistry. In bacteriology, gelatin can be used as a component of culture media for species differentiation. Additionally, as a biocompatible polymer, gelatin has been used as a delivery vehicle for the release of bioactive molecules and in the generation of scaffolds for tissue engineering applications. Gelatin proteins are also used as additives in purified, recombinant proteins and antibodies. Animals or humans exposed to gelatins may invoke antibody response. Often the gelatin must be removed prior to such applications. Antibodies to gelatins were produced to detect the presence of gelatins in biolgocial samples and or to verify their removal during bioprocess development. Applications: Suitable for use in ELISA. Other applications not tested. Recommended Dilutions: ELISA: 1:1000-1:10,000; Coat gelatin antigen at 5-10ug/ml. Optimal dilutions to be determined by the researcher. Storage and Stability: Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.