KAP2@vaxa.york.ac.uk (04/26/91)
With regard to the enquiry about nuclear DNA measurements using flow cytometry of leaf cells, it seemed to me that the amount of chloroplast DNA in leaf cells may be very significant in relation to the amount in the nucleus so i did a VERY rough calculation. I know mature Arabidopsis leaf cells have about 120 chloroplasts. assuming the size of the genome is about 130kB and the copy no per plastid is about 50 ( both of these values are estimates, others may have accurate values), then there would be 6000 copies of chloroplast DNA per mesophyll cell which approximates to about 0.9 pg which is well in excess of published nDNA levels for Arabidopsis. so using intact cells for nuclear DNA esimates may be very inaccurate. any comments on all this would be interesting regards kevin pyke york, england