ALEX B. NOVIKOFF, PH.D. Waldemar Medical Research Foundation, Port Washington, New York. Formerly in the Departments of Pathology and Oncology and of Biochemistry, University of Vermont College of Medicine, Burlington, Vt.
In this chapter we shall distinguish between histochemical and cytochemical methods, not in the fashion of Brachet (35) or of Schneider and Hogeboom (284) and Dounce (84), but simply on the basis of the organizational level studied: histochemistry deals with tissue components, cytochemistry with cell components. We shall take these terms to include all the different techniques used to elucidate the chemical nature of cell structures and cell products--the physical methods described in this book, the method of differential centrifugation, the staining methods with which this chapter deals, and still other methods not considered in this volume.
In 1936, when L. Lison monumental "Histochimie animale" (192) was published, histochemical staining methods were almost synonymous with histochemical methods generally; little more than 20 of the 320 pages of the book were devoted to other methods. Thirteen years later D. Glick "Techniques of Histo- and Cytochemistry" (108) appeared; some 80 per cent of it was devoted to other techniques. The expansion of these other techniques has continued to the present day; all but two chapters of this volume deal with them. Yet publications dealing with staining methods still outnumber, by far, those which deal with other histochemical methods. Investigators from every biological and medical discipline are using staining methods. Largely as a result of this increased use of histochemical staining methods, a new society