in order to study the ontogeny of various structural and antigenic components of the basement membrane zone of human skin , we have examined skin specimens from 20 aborted fetuses ranging in gestational ages from 6 to 25 weeks , utilizing light microscopy , transmission electron microscopy , and indirect immunofluorescence with antibodies to bullous pemphigoid antigen , laminin , type iv collagen , and to the antigen defined by kf-1 monoclonal antibody .
C0004799
basement membrane
C0022984
laminin