ROLE OF BUFFERS IN LUNG FIXATION WITH GLUTARALDEHYDE AND OSMIUM TETROXIDE

In double-fixation of lung with glutaraldehyde and osmium, spherical electron dense granules appear as artifacts on the alveolar surface and on erythrocytes. We have tested the effect of six different buffers during glutaraldehyde prefixation, washing, and osmium postfixation. The granules were found to appear only when tissue prefixed in glutaraldehyde is postfixed with osmium in phosphate buffer. The possible significance of these granules is discussed. Further, the influence of different fixatives and stains on extracellular alveolar coatings as well as their possible relationship to pulmonary surfactant are discussed. © 1968 Academic Press, Inc.