RT Journal Article SR Electronic(1) A1 van Rensburg, A. J.YR 1969 T1 Infection of Spheroplasts With Deoxyriboneucleic Acid From a Proteus Bacteriophage JF Journal of General Virology, VO 5 IS 3 SP 437 OP 441 DO https://doi.org/10.1099/0022-1317-5-3-437 PB Microbiology Society, SN 1465-2099, AB Infection of protoplasts and spheroplasts by isolated bacteriophage DNA with production of whole phage has been reported for a number of organisms (Riggs & Rosenblum, 1969). This phenomenon has not previously been described in Proteus strains. DNA was prepared from phage 13 vir (Prozesky, de Klerk & Coetzee, 1965) by the technique of Gierer & Schramm (1956). The concentration of DNA, determined by optical extinction at 260 nm. (1 μg. DNA/ml. = 0.0205 absorbency units), ranged from 200 to 600 μg./ml. Sedimentation coefficients of the DNA at concentrations of 10 to 50 μg./ml. were determined in a Spinco model E ultracentrifuge (Rosenblum & Schumaker, 1963). The DNA was homogeneous and an average molecular weight of 26.3 × 106 was calculated. Sedimentation of the DNA through an alkaline sucrose gradient revealed no single-strand breaks., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-5-3-437