DELOCALIZED VERSUS LOCALIZED PICTURES IN RESONANCE ENERGY TRANSFER

2 Spink, W. W., and V. Ferris, Science, 102, 221 (1945). 3Bondi, A., Jr., and C. C. Dietz, J. Bacteriol., 55, 843 (1948). 4Pollock, M. R., in Drug Resistance in Microorganism: Mechanisms of Development, Ciba Foundation Symposium, ed. Wolstenholme and O'Connor (London: Churchill, 1957), p. 78. 6 Barclay, W. R., in 12th Conference on Chemotherapy of Tuberculosis, Atlanta, Georgia, February, 1953, p. 249. 6Kushner, D. J., Arch. Biochem. Biophys., 58, 347 (1955). 7Hancock, R., Abstracts, 5th International Congress of Biochemistry, Moscow, August, 1961, p. 164, No. 7, 40, 1226. 8 Landy, M., N. W. Karkum, E. J. Oswald, and F. Streightoff, Science, 97, 265 (1943). 9 Saz, A. K., and L. M. Martinez, J. Biol. Chem., 223, 285 (1956). 10 Lightbown, J. W., Giorn. ltal. Chemioterap., 4, 22 (1957). 11 Erythromycin-A or erythromycin. The nonradioactive erythromycin was a generous gift of Eli Lilly and Co. 12 Haight, T. H., and M. Finland, Proc. Soc. Exptl. Biol. Med., 81, 175 (1952). 13 Streightoff, F., Butler Univ. Bot. Studies, 13, 179 (1958). 14 Brock, T. D., and M. L. Brock, Biochim. Biophys. Acta, 33, 274 (1959). 15 Spizizen, J., these PROCEEDINGS, 44, 1072 (1958). 16 Young, F. E., and J. Spizizen, J. Bacteriol., 81, 823 (1961). 17 Obtained through the courtesy of Dr. Eugene Nester. 18 Young, F. E., and J. Spizizen, J. Bacteriol., 86, 392 (1963). 19 Kaneda, T., J. C. Butte, S. B. Taubman, and J. W. Corcoran, J. Biol. Chem., 237, 322 (1962). 20 Methylcyclohexane: methylisobutyl ketone: t-butanol:phosphate buffer, pH 7.0, 0.1 M (75:15:10:25 v/v). 21 Davidson, J. D., Proceedings, University of New Mexico Conference on Organic Scintillation Detectors, August, 1960, p. 237. 22 Landman, 0. E., and S. Halle, Abstracts, 8th International Congress for Microbiology, p. 28 (1962). 23 Gots, J. S., Proc. Soc. Exptl. Biol. Med., 60, 165 (1945). 24 The dimensions as obtained from electron micrographs of this strain are approximately 2.3 X 1.1 i. Assuming a cylindrical shape, the total volume of each bacterium would be 2.2 3, and the cellular fluid volume would be 1.7 A3 (assuming 76% intracellular fluid volume) per bacterium or 1.7 X 1011 ,UA per 10ll bacteria (1.7 X 10ll,43 = 0.17 ml). At an external erythromycin concentration of 1 &g/rml, the sensitive bacteria have taken up 9.9 iug/1011 bacteria or 9.9 sg per 0.17 ml of intracellular fluid (57 times concentrated). At the same external eyrthromycin concentration, the resistant strain has only taken up 3.4 Mug of erythromycin per 1011 bacteria. 25 So, A. G., and E. W. Davie, Biochemistry, 2, 132 (1963). 26 Unpublished data.