INVESTIGATION OF TUNICHROME AND ITS RELATION TO VANADIUM IN LIVING ASCIDIAN BLOOD-CELLS AND THEIR LYSATES

1. Results presented in this paper show that there is no evidence for tunichrome in intact cells of the two Ascidiidae species Ascidia cerat odes or Phallusia julinea. 2. The yellow fluorescence of ascidian bloo d cells cannot be unequivocally ascribed to the yellow fluorescent tun ichrome and should not be used as evidence for the compound in vivo. 3 . Spectrofluorometric emission peaks reported by previous workers as e vidence of tunichrome in vivo were in the same positions as water Rama n bands. 4. Yellow fluorescence has been observed in the blood cells o f species in which tunichrome has not been found, for example Ciona in testinalis and Pyura stolonifera. 5. The accumulated data suggest that both the lysis of morula [low in vanadium (V) and high in tunichrome precursor contents] and compartment-signet ring (high in V content) ce lls are necessary for the formation of tunichrome.