Ultrastructural localization of intracellular immune globulins in plasma cells and lymphoblasts by enzyme-labeled antibodies.

Abstract

Techniques for localization of immune globulins by specific antibodies labeled with peroxidase or alkaline phosphatase were applied to spleens of rabbits hyperimmunized against various antigens. Best results were obtained with tissue blocks or thick sections after fixation in 1% formaldehyde (freshly prepared from paraformaldehyde) in cacodylate buffer with sucrose. The edges of blocks gave adequate penetration, comparable to thick sections. Ultrathin frozen sections which were reacted directly with labeled conjugate were less successful and glycol methacrylate sections failed to stain. Results were 3-fold: (1) immune globulins were demonstrated in ergastoplasmic cisternae, perinuclear space and Golgi apparatus of plasmocytes; (2) associated ribosomal staining varied somewhat with fixation and osmolarity of fixative; (3) lymphoblasts were shown to contain antibody. Generalized cytoplasmic staining was observed in the lymphoblasts, with no localization in the ergastoplasm and with no staining of control preparations. The significance of ribosomal and lymphoblast staining is discussed in relation to cell differentiation and the development of the immune response.