s 



o 



T 

 30 



60 



I I I 1 I I I r 

 90 120 150 180 210 240 270 300 330 1050 



Seconds After Sperm Addition 



Fig. 2. 



Analysis of reduced pyridine nucleotide at various times 

 after fertilization of S. purpuratus. (Fig. 2, Epel, Biochem. 

 Biophys. Res. Comm. 17, 69, 1964; reproduced witJi per- 

 mission of Academic Press.) 



Totol Reduced Pyridine Nucleotide (10 moles/10 cells) 

 Fig. 3. 



Linearity of cell fluorescence and reduced pyridine nu- 

 cleotide at various times following fertilization. 



E 



'o 



u 



in 

 O 



E 



'o 



20 40 60 80 100 120 140 

 Seconds After Sperm Addition 

 Fig. 4. 



Analysis of oxidized pyridine nucleotide following fertili- 

 zation of 5. purpuraius (Figs. 1, 2 and 4 are from separate 

 experiments and not strictly comparable). 



20 



