With the primary objective of comparing the UV-B induced changes in algae having different thylakoid  organization, three species of marine microalgae, Chlorella salina, Dicrateria inomata and Isochrwsis galbana in pure cultures were screened for their UV-B sensitivity based on the changes in the rate of photosynthetic 0₂ evolution. Chlorella was found to be highly sensitive  whereas dicrateria was moderately sensitive and Isochysis was resistant.

Under short term UV-B treatment (5 W.m² ) there was no significant change in the level of pigments. But the cellular protein content showed drastic changes in both Chlorella and Dicrateria while Isochysis showed only a marginal change. Absorption spectral studies in Chlorella cells revealed only marginal changes in the major chlorophyll absorption bands. In Dicrateria and Isochysis cells, the levels of major red and blue peaks had decreased. In addition, a shift towards long wavelength of the red absorption peak was also observed. Flourescence excitation spectra for F-682 in Chlorella cells showed no significant change in the excitation characteristics but Dicrateria and Isochrysis cells showed a progressive reduction in the level of 530 and 590 nm excitation peaks.