Table 1.

DNA C‐values for Arabidopsis thaliana estimated by Feulgen photometry (FE), flow cytometry (FC), or the molecular methods: reassociation kinetics (RK) and quantitative gel blot hybridization (GBH)

	1C DNA amount		Size standard and
Technique and reference	pg	Mb	1C DNA amount
RK (Leutwiler et al., 1984)	0·082	80·0*	E. coli = 4·64 Mb
	[0·071	70·0*	E. coli = 4·10 Mb]
GBH (Francis et al., 1990)	0·051	50·0*	–
FE (Bennett and Smith, 1991)	0·175*	171·5	Vigna = 0·53 pg
FE (Krisai and Greilhuber, 1997)	0·167*	163·7	Allium = 16·78 pg
			Pisum = 4·42 pg
FC : MI (Galbraith et al., 1991)	0·085*	83·0	Yeast = 13·39 Mb
	[0·095	93·0	Yeast = 15 Mb]
	0·160*	156·8	CRBC = 1·165 pg
FC : Hoechst (Galbraith et al., 1991)	0·165*	161·7	CRBC = 1·165 pg
FC : DAPI (Galbraith et al., 1991)	0·170*	166·6	CRBC = 1·165 pg
FC : PI (Arumuganathan and Earle, 1991)	0·150*	147·0	CRBC = 1·165 pg
FC : PI (Marie and Brown, 1993)	0·165*	161·7	CRBC = 1·165 pg
FC : PI (Dolezel et al., 1998)	0·195*	191·1	Pisum = 4·55 pg
	0·185*	181·3	Allium = 16·78 pg
FC : PI (this work)	0·153*	150·0	Drosophila = 180 Mb
	0·167*	163·7	CRBC = 1·165 pg
	0·160	157·0	C. elegans = 100 Mb

Fluorochromes used for FC were: mithramycin (MI), 4′,6‐diamidino‐2‐phenylindole (DAPI), Hoechst 33258 (Hoechst), propidium iodide (PI). Molecular biologists gave estimates in Mb and others mainly in pg (1 pg = 980 Mb; Cavalier‐Smith, 1985)—original form marked with an asterisk. Values from Arumuganathan and Earle (1991) using 1 pg = 965 Mb (Strauss, 1971) have been corrected. Size standards were Allium cepa (Allium); Caenorhabditis elegans strain Bristol N2 (C. elegans); chicken red blood cells (CRBC); Drosophila melanogaster strain Iso‐1 (Drosophila); Escherichia coli (E. coli); Pisum sativum (Pisum); Saccharomyces cerevisiae (Yeast); or Vigna radiata ‘Berken’ (Vigna). For E. coli and yeast, genome size was later established by DNA sequencing (Goffeau et al., 1996; Blattner et al., 1997), so the original estimate in parentheses is preceded by a recalibrated value based on this.