Estimation of the mean caliper diameter of cell nuclei

Abstract
Morphometric studies of lung tissue in which the number of cell nuclei (therefore cells) are determined require the determination of the mean caliper diameter for each type of cell nucleus studied. The mean caliper diameter for the 5 most common classes of cells found in the gas exchange portion of rat lung was determined. This was done by serially sectioning through 10 nuclei from each class of cells and constructing wax models of the nuclei. Most of the nuclei were triaxial ellipsoids and direct measurements taken from the models were used to calculate the following estimated overall mean caliper diameters (.+-. SE): alveolar type I nuclei, 7.7.97 .+-. 0.2 .mu.m, alveolar type II nuclei, 6.77 .+-. 0.19 .mu.m, interstitial cell nuclei, 7.64 .+-. 0.35 .mu.m, endothelial cell nuclei, 7.22 .+-. 0.19 .mu.m and alveolar macrophage nuclei, 7.65 .+-. 0.17 .mu.m.