STUDIES ON THE ELECTRICAL CHARGE OF BACTERIOPHAGE

A common laboratory procedure for the determination of the charge carried by a dye is to dip a strip of blotting paper in the dye solution and observe whether or not the stain passes into the negatively charged paper with the water. Methylene blue, a positively charged dye, is strongly adsorbed by the paper and therefore does not rise to any extent above the solution level, although the water will rise several centimeters. On the other. hand, a negatively charged dye such as eosin will climb a con-siderable distance in the paper with the water. Bedson and Bland (1929) applied this method to the deter-mination of the electrical charge carried by virus particles and their results are quite consistent with those obtained by other workers from cataphoresis experiments. Todd (1927) by means of cataphoresis studies, found that anti-shiga bacteriophage carries a negative charge between pH 3.6 and 7.6. As a result of similar studies Krueger, Ritter and Smith (1929) reported that several races of anti-coli 'phage which they have studied carry a negative charge from pH 9.0 to 3.4 and are positively charged below 3.4. Natarajan and Hyde (1930) likewise reported that small plaque anti-coli 'phage carries a negative charge below pH 8.3, and large plaque anti-coli 'phage a negative charge below 6.1 while both seem to be amphoteric above these values. Anti-Flexner 'phage is negative between pH 5.4 and 9.3 and anti-typhosus 'phage between pH 4.9 an