78 



MARY ELMORE SAUER AND DONALD DUNCAN 



TABLE I 



Staining Reactions of the Bodies Which Appear in 

 THE Cytoplasm After X-Irradiation 



Method 



Ceiitei 



Periphery 



Color 



Significance 



Color 



Significance 



Hematoxylin-eosin 



Toliiidine blue 



Feulgen's 

 Omitting 



hydrolysis 

 After DNase 

 After RNase 



Methyl green- 

 pyronin 

 After DNase 



After RNase 



May-Griinwald- 



Giemsa 



After DNase 



After RNase 



Purple Basophilic 



Deep blue Presimiably 



nucleic acid 

 Deep red 



No red 

 No red 

 Deep red 



Deep green 



No green 

 on slide 

 Deep green 



DNA 



DNA (polymerized? 



Black 



Black 



Mostly red, 

 but a few 

 remain black 



DNA and RNA? 



Red Acidophilic 



Pale blue — 



Green 



Green ) Not DNA 

 Green 



Red 



after digestion with RNase indicate that it is RNA. The deep purplish black 

 staining of the center or often of the entire body with the May-Griinwald 

 and Giemsa stain would be consistent with this conclusion. Jacobson and 

 Webb ( 1952) found that chromatin changes in its reaction to this stain dur- 

 ing the sequence of mitosis from red in the interphase to black during meta- 

 phase. These authors apparently demonstrate that black indicates presence 

 of RNA in addition to DNA, but the specificity of this has been questioned 

 (Swift, 1953; Theorell, 1955). In our hands black of the metaphase was 

 more resistant to each type of nuclease than were the other cellular elements 

 and that of the inclusions was even more resistant than were the metaphases. 

 Following DNase, the bodies stained as black as before; following RNase, 

 digestion was incomplete, some resistant bodies always remaining. 



The response of neural tube cells of embryos exposed for as long as 12 

 hours to tritiated thymidine resembled the response to x-ray (Sauer and 

 Walker, 1961). However, there was no cessation of mitosis in the tritium- 



