1960 31 121 The weight of 1 per cent of the particle [sc. T2 phage] is 1·2 Md. [Note] Md = megadaltons or 1,000,000 molecular weight units.
1973 Apr. 22/2 The molecular weight of the E. coli chromosome is 2,500 megadaltons.
1987 D. J. Weatherall et al. (ed. 2) I. v. 251/2 Virulence of Y. pseudotuberculosis and Y. enterocolitica is mediated by carriage of a 40–50 megadalton plasmid.