ABSTRACT
Chromosomal proteins have been assigned to two major categories, histones and nonhistones. Antigens are immunochemically localized by the peroxidase anti-peroxidase (PAP) method. The PAP method of immunochemical localization provides a rapid and sensitive means of detecting antigenic proteins on nitrocellulose sheets. Transferred nonhistone proteins were incubated with lactoferrin and bound lactoferrin was identified immunochemically. Because of the great heterogeneity, difficult solubility characteristics, and small quantities of many nonhistone proteins immunochemical methods are particularly important tools in uncovering information on chromatin structure and function. The great heterogeneity of the nonhistone proteins and the inability to readily determine their biological activities has made it difficult to identify and follow individual proteins with respect to distributions in different tissues and states of differentiation. Complement fixation is one of the most widely employed immunological methods in chromatin research.
