%0 Journal Article %A Garwes, D. J. %A Pike, Brenda V. %A Wyld, Sara G. %A Pocock, D. H. %A Gourlay, R. N. %T Characterization of Mycoplasmatales virus-laidlawii 3 %D 1975 %J Journal of General Virology, %V 29 %N 1 %P 11-24 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-29-1-11 %I Microbiology Society, %X SUMMARY Purified preparations of Mycoplasmatales virus-laidlawii 3 were negatively stained and studied by electron microscopy. They were seen to consist of uniform sized particles having a polyhedral head, 57 nm by 61 nm, and a short tail, 25 nm long, joined to the head at one vertex by a collar. The particles were shown to have buoyant densities of 1.477 g/ml in CsCl, 1.32 g/ml and 1.26 g/ml in potassium tartrate and a sedimentation coefficient, s 20, w, of 290 ± 13. They are composed of 35.2% double-stranded DNA and five structural polypeptides with approximate mol. wt. of 172000, 81000, 73000, 68000 and 43000. The classification of the virus from its morphology and chemical properties is discussed. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-29-1-11