Treatment of H. chlorum membrane preparations with diethyl ether of high degrees of water saturation raised the bacteriochlorophyll (BChl) g′ mole fraction, as determined by HPLC analysis of their acetone extracts, toward a level of 40% of total BChl g or higher. Starting from pure BChl g, the BChl g′ mole fraction should never exceed 24.6% which is the equilibrium value in diethyl ether. The existence (and possible functioning) of BChl g′ in vivo is thus unequivocally demonstrated.
