Flow cytometric analysis of SG-stained chloroplasts. (A-F) Chloroplasts isolated from 20-day-old seedlings treated with and without DNase and stained with the indicated concentrations of SG. Differences in cpDNA content (G) and PPoD (H) for chloroplasts isolated from seedlings at 14 and 20 days after imbibition. (A-F) Chloroplasts were fixed in glutaraldehyde. (G and H) Chloroplasts were not fixed. At least 6000 chloroplasts were analyzed for all samples.