Quantitative Aspects of Nuclear Nucleoproteins

Publisher Summary The nucleus is usually considered as playing a dual role in the cell. It is the carrier of genetic specificity and the organization center for cell function. Techniques of importance in the study of nucleoproteins include methods for determining the natural ultraviolet absorption of living and fixed cells and also the absorption in visible light of cells fixed and stained with acid or basic dyes and various cytochemical reactions. The photometric methods are applied to cells, including two recent symposia. Much of the modern quantitative cytology depends upon the validity of these techniques. Cytophotometric methods are simple in principle; and yet the possible sources of error are so numerous and difficult to estimate under practical measuring conditions that there are few adequate studies of the accuracy and reproducibility available. This chapter presents the tests devised to check the actual performance of measuring instruments. Obstacles, such as inhomogeneity, which has been estimated on theoretical grounds to give very large errors in measurements on nuclei, are discussed.