Immunohistochemical detection of fibrillar collagens in tissue sections and in culture cells

We evaluated conditions for optimal immunostaining for Type I procollagen a nd Type III collagen in tissues with high content of these fibrillar collag ens. We tested polyclonal and monoclonal antibodies on formalin fixed, para ffin embedded sections and frozen sections from avian tendons and gizzard a nd on tendon cell cultures grown on glass slides. We also evaluated procedu res for antigen unmasking. We obtained the strongest specific staining with monoclonal antibodies to both collagen types using frozen tissue sections or methanol-acetone fixed tendon cell cultures. The use of antigen unmaskin g was not only unnecessary, but also undesirable as it led to the detachmen t of sections.