F. I. TSUJI, A. M. CHASE AND E. N. HARVEY 135 



identical in position to the yellow color (R; = 0.5-0.6), and one of 

 blue fluorescence (R/ = 0.2). The yellow-brown area at the solvent 

 front showed only a weak, diffuse yellow fluorescence. On moistening 

 the paper with luciferase solution, a single intense luminous area was 

 observed which corresponded exactly to the area of the yellow color 

 and yellow fluorescence. The yellow color, yellow fluorescence, the 

 luminescence with luciferase and the Rf of 0.5-0.6 in this developing 

 solvent can, therefore, be considered characteristic properties of Cy- 

 pridina luciferin. Of these, luminescence with the enzyme is the ulti- 

 mate criterion. The other materials on the paper are presumably im- 



FiG 1 Diagram showing paper chromatogram of doubly cycled luc.fenn devel- 



■ oped with ethyl acetate-ethyl alcohol-water mixture. A represents origm; 



band B, an impurity, shows only blue fluorescence; band C. luciferm, shows 



yellow color and yellow fluorescence; D, a yellow-brown impurity; and E 



represents solvent front. 



purities. In similarly developed chromatograms, the yellow luciferin 

 area of the paper was cut out and eluted with methyl alcohol. The 

 yellow methanol solution was evacuated to dryness and the residue 

 used for spectrophotometric studies (to be discussed in a later sec- 

 tion) and for amino acid analysis by the chromatographic method ot 



Moore and Stein (1951). 



Efforts have recentlv been made to isolate luciferin by ion-exchange 

 resins in amounts larger than heretofore obtainable with paper chro- 

 matography and paper electrophoresis. Fine mesh Dowex 50 of vari- 

 ous cross-Hnkages was tried in a column 2.26 sq cm X 9.0 cm. Lucif- 

 erin was taken up readily from 0.1 N HCl at room temperature 

 (23° C) in a system in which air had been replaced by pure hydro- 

 gen. Elution was attempted, using successively oxygen-free 0.1 N 

 HCl 1 N HCl, 3 N HCl, saturated NaCl, phosphate buffer pH 6.8, 



