APPLICATION OF THE MEMBRANE FILTER FOR THE QUANTITATIVE STUDY OF TRANSFORMATIONS WITH PARTICULAR REFERENCE TO PHENOTYPIC EXPRESSION OF AN ERYTHROMYCIN-RESISTANCE MUTATION.

Iyer, V. N. (University of Rochester, Rochester, N.Y.). Application of the membrane filter for the quantitative study of transformations with particular reference to phenotypic expression of an erythromycin-resistance mutation. J. Bacteriol. 84:326-330. 1962.-A technique using membrane filters for quantitative studies of transformation of pneumococci is described and some possible applications discussed. This method has been found amenable to the study of the integration and phenotypic expression of an erythromycin-resistance mutation of pneumococci which is characterized by a low frequency of transformation and delayed expression. The expression of survival occurs prior to the expression of colony-forming ability in the presence of erythromycin.