The main purpose of the two volumes on Immunochemistry of the Extracellular Matrix is to describe state of the art methods, which have been proven to provide antibody reagents of defined specificity to collagens as well as other glycoproteins found in association within connective tissue. The isolation and purification of collagens, procollagens, and related connective tissue proteins are described for several tissues, tissue culture cells and species. Immunization with these collagens in laboratory animals yields antibodies with different characteristic specificities: to the procollagen extension fragments, the non-helical segments of the a-chains, to helical and denatured determinants.