Influence of Selective Light Scattering on Measurements of Absorption Spectra of Chlorella.

Experimental information about the light scattering characteristics of biological cells is surprisingly scarce. Even though all measurements of absorption spectra of intact biological structures must be influenced to some extent by scattering, there have been few investigations dealing specifically with scattering by cell suspensions. However, recent experiments have revealed that light absorbing cells and cellular components in suspension scatter light with a strong spectral selectivity (5, 6). Scattering maxima occur on the long wave length sides at absorption maxima. Other studies have demonstrated that this selective scattering can influence measurements of absorption spectra, shifting apparent band positions by 10 to 15 ??? (7, 8). The present paper describes further investigations of phenomena related to selective scattering. We attempted to obtain information about light scattered at small angles to an incident beam from suspensions of Chlorella pyrenoidosa Chick (Emerson strain) by using special experimental methods to measure absorption spectra. We have made use of the fact that the effects of