114 M. N. MEISSEL, E. M. BRUMBERG, T, M. KONDRATJEVA AND I. J. BARSKY 



200 



« ; 



309 



349 



389 



429 



A (m/Lt) 



Fig. 3. — Ultraviolet fluorescence spectra of the blood plasma of normal and irradiated 

 rats. 1-normal (control), 2-4 hr after irradiation; 3-27 hr after irradiation; 4-shift of 



spectra after u.v. irradiation. 



With the aid of the photoelectric inicrospectrofiiiorometer descrihed 

 above Agroskin d. al. (1960) investigated the low temperature fluor- 

 escence sx^ectra of solid specimens of ribo- and deoxyribonucleic acids 



310 



340 



430 



460 



370 400 



A (m//) 



Fig. 4. — Fluorescence spectra of ribonucleic acid (from yeast) and of its comiDonent 



bases (excitation with A = 2(J0 to 280 lufj.). 

 A-adenine, G-guanine, U-uracil, C-cytosine. 



and their separate components. Of the data obtained the most interest- 

 ing from the standpoint of the subject under discussion ai*e the spectra 

 of the nucleic acids and their bases (Figs. 4 and 5). It was found that 

 the component bases of the nucleic acids and also the nucleosides and 



