Cytochemistry of the Lymphocytes 37 



cytes (chronic lymphocytic leukemia) have been observed following ex- 

 posure to ribonuclease in that the granulocytes were methyl green-labile and 

 the lymphocytes methyl green-resistant. 58, 103 Further investigations are neces- 

 sary to substantiate these differences in methyl sreen staining. 



Proteins and Amino Acids 



Protein-bound amino groups can be demonstrated in the cytoplasm and 

 nuclei of the lymphocytes (Fig. 3-25) in blood films 9 following Weiss's 

 method 1 "'' for these reactive groups. The cytoplasm stains moderately in con- 

 trast to the faint reaction of the nucleus of these cells (Fig. 3-25) . The cyto- 

 plasm is more intensely stained in the larger lymphocytes than in the small 

 lymphocytes, and it appears that this staining reaction tends to parallel the 

 RNA content of the cytoplasm of these cells. In most instances the cyto- 

 plasm and nuclei of the lymphoid cells of the spleen stain strongly for 

 protein-bound amino groups. 109 



Only traces of histidine can be localized in the cytoplasm of the lympho- 

 cyte in blood films 1 ' following the reaction of Burstone. Arginine can be 

 demonstrated in the cytoplasm, nuclei, and nucleoli of the lymphocytes in 

 both blood 108 and lymphatic tissue 9 and appears to parallel the intensity of 

 the reactions for nucleoproteins. ! * Tyrosine cannot be demonstrated in the 

 lymphocytes of the blood following the Millon reaction. 10 ' 1 At the present 

 time protein reactions appear to afford little help in the differential diagnosis 

 of lymphatic diseases. 



Sulfhydryl Groups 



Lymphocytes of the blood and lymphatic tissue exhibit a relatively weak 

 reaction for sulfhydryl groups following the DDD method of Barrnett and 

 Seligman, 4 - s - ! ' v -- ls - !,T the RSN method of Mauri and others, 2 "' 66 and the 

 older ferri-ferrocyanide procedure. 1 ' ls '•'" Normal lymphocytes in both the 

 blood (Figs. 3-23, 3-24) and lymphatic tissue (Fig. 3-37) reveal a pale, dif- 

 fuse staining of their cytoplasm and a less intense staining of their nuclei 

 following the DDD 4 ' s - '•'■ ;,T and RSN 26, ,1(; methods. However, it appears that 



Fig. 3-25. Small lymphocyte stained for protein-bound amino groups by the method 

 ol Weiss. The nucleus is only faintly stained in contrast to the darker staining of the 

 cytoplasm and nucleoplasm. 



Fig. 3-26. Lymphocyte stained for nonspecific esterase using the indoxyl acetate sub- 

 strate. Indigo blue crystals have a distribution similar to mitochondria but are not local- 

 ized in these organelles. 



Fig. 3-27. Demonstration of nonspecific dehydrogenase activity with a modified nitro 

 BT procedure in a normal small lymphocyte. Dehydrogenase can be localized to the 

 mitochondria; however, it is uncommon lor normal lymphocytes to be stained by this 

 method. 



