202 



FIREFLY LUCIFERIN 



Fig. 



<Mhy\ 



RIBOFLAVIN 



J I I l_J L 



l/^ 



J 1 I L 



LUCIFERIN 



5 6 7 8 9 10 II 12 13 14 15 

 WAVELENGTH (MICRONS) 



3. The infrared absorption spectra of riboflavin and luciferin. Samples were 

 prepared in dry form. In order to compensate for the pronounced scattering, 

 the compensating beam was attenuated. Variations in absorption were thus 

 amphfied. On tlie other hand, this procedure made it impossible to deter- 

 mine the relative extinctions at difl^erent wavelengths quantitatively. 



Fig. 4. Migration of luciferin in an electric field as a function of pH. Small T 

 tubes 18 cm in length were filled with ca. 4% agar adjusted to various pH's 

 with phosphate buffer (ca. 0.01 M) in ca. 0.1 M KCl. A luciferin solution 

 was introduced into tlie middle of the tube through the base of the T with 

 a hypodermic needle. One hundred thirty-five volts were applied and the 

 migration was followed by observing the position of fluorescence. 



