vi Preface 



methods that are not overly complicated or impredictable. It is hoped 

 that the technician will watch the literature for modifications and im- 

 provements of "standard" technics; in this way his work can be kept 

 up to date and perhaps simplified. Methods for fixation are fairly well 

 established, and only occasional variations appear from time to time. 

 The section on fixation presented here is as modern as the author can 

 make it, and it includes a brief description of the chemicals employed. 

 The perfecting of old staining technics, as well as the development 

 of new ones, continues to appear in the literature; an attempt has been 

 made to incorporate the latest procedures and modifications in this 

 book. The discussion of fixation and its solutions and of dyes and their 

 action is given for the benefit of those who cannot, or will not, seek out 

 the source material. 



Certain important fields are not covered in this book either because 

 they are not widely used methods or because they are considered too 

 highly specialized. A few of these fields are: vital staining — the selec- 

 tive dyeing of certain isolated cells while alive; tissue transplantation 

 — transferring a tissue from its normal location to a different one, 

 where it can be observed more easily; tissue culture methods — growing 

 cells in artificial habitats; tracer technics — using radioactive isotopes 

 which can be traced in the body; and microincineration — the study 

 of minerals in the tissue. However, three fields of increasing popu- 

 larity and importance are introduced — autoradiography, histochemical 

 methods, and electron microscopy. The coverage on these three sub- 

 jects is held to a minimum, but appended references and bibliography 

 can help a technician find more extensive source material. 



A logical arrangement of special staining methods is hard to come 

 by, so the author has followed her own inclinations. Some sections 

 are organized by related tissues, others by related methods. The latter 

 Avas considered desirable for such processes as silver impregnation, 

 metachromasia, and methods using Schiff's reagent. It has been im- 

 possible to draw a hard and fast line, but it is hoped that cross- 

 referencing and indexing will provide the answers. The author has 

 had personal experience with most of the methods, and has also tried 

 to include modifications which might appeal to other adventurous 

 technicians. 



The book is divided into four parts: /. General procedures and con- 

 siderations which every tissue technician should know and imderstand. 

 This part will be of particular value in a beginners' course; //. Special 

 staining methods for most tissues. The idea here is that an instructor 

 can choose a few favorites for teaching purposes to roinid out a course. 



