Differential light-scattering of granal and agranal chloroplasts and their fragments

Intact (class-A) granal and agranal maize chloroplasts and chloroplast fragments were examined for differential scattering of circularly polarized light (measured at 90 degrees) and c.d. (circular dichroism) (measured at 0 degrees) by using a modified spectropolarimeter with a large acceptance angle. Useful c.d. information was obtained by making corrections for scattered light. Chloroplast fragments exhibited a large and characteristic differential scattering of circularly polarized light recognized in the presence of granal chloroplasts. It is confirmed that agranal chloroplasts do not have the intense 682 nm c.d. peak that is assigned to the presence of grana.