4.5 



4.0 



3.5 



3.0 



UJ 



2.5 - 



2.0 



1.0 - 



0.5 



210 



230 250 270 290 310 



Wavelength in millimicrons 



- 1.0 



0.5 



330 



Figure 11-19. Ultraviolet Absorption Spectra of Several Nucleic Acid 



Bases and Protein Amino Acids. Adenine ( ), cytosine ( ), 



tyrosine (....), and phenylalanine ( — — ). (From Blout, E. R., 1953. 

 "Ultraviolet Microscopy and Ultraviolet Microspectroscopy," in Lawrence, 

 J. H. and Tobias, C. A. (Eds.), "Advances in Biological and Medical 

 Physics," 3, Academic Press, New York, N. Y., Fig. 1, p. 288.) 



SURVEY OF CYTOLOGICAL TECHNIQUES / 239 



