CHAPTER 4 



ELECTRON MICROSCOPY OF THE 

 LYMPHOCYTE* 



FRANK N. LOW 



The structure of blood cells, including the lymphocyte, has been observed 

 with the electron microscope by numerous investigators in recent years. 110 An 

 account of the ultrastructure of blood lymphocytes, somewhat more detailed 

 than other contributions, may be found in the description of normal and 

 leukemic human blood by the writer and James A. Freeman. 11 This chapter 

 recapitulates the essential points of the original description, adds certain 

 details recently clarified, and compares the ultrastructure of the lymphocyte 

 with that of certain other blood cells. The electron microscopic blood pic- 

 ture in normal and leukemic human blood is interpreted with reference to 

 the probable relationship of the lymphocytic series to the other develop- 

 mental series of blood cells. 



MATERIALS AND METHODS 



Peripheral human blood was used exclusively in this study. Samples were 

 obtained by the Freeman method 11 which is based on careful use of non- 

 wetting agents and refrigeration. This method does not add any foreign 

 substance to the blood prior to fixation. The remainder of the technique, 

 including buffered Os0 4 fixation, 1 -' was empirically modified to facilitate 

 handling of the buffy coat but did not differ in any essential respect from the 

 routine preparatory techniques of electron microscopy described by Far- 

 quhar. 13 



Electron micrographs differ from light micrographs in certain ways that 

 may lead to significant interpretative errors, unless proper caution is exer- 



* This work was supported in part 1>\ (.rant H-1663 from the National Institutes of Health, 

 United States Public Health Service. 



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