ADSORPTION OF PHAGE TO HOST CELL 151 



from 5 to 12 using phage T2 and E. coli B. Maximum adsorp- 

 tion occurred at pH 6 to 8. The pH dependence suggested to 

 Tolmach and Puck that carboxyl and amino groups are pri- 

 marily involved in phage T2 adsorption and that phosphoric, 

 sulfhydryl, and phenolic groups are unimportant. 



This notion was tested by studying the adsorption of phage to 

 host cells which had been treated with various reagents designed 

 to eliminate specific chemical groupings. The results are given 

 in Table XIII. They were interpreted by the authors as indi- 

 cating that adsorption of phage T2 involved primarily carboxyl 

 groups of the bacterial surface while adsorption of Tl involved 

 amino groups. 



TABLE XIII 



The Binding of Phages Tl and T2 to Chemically Modified Host Cells" 



" From L. J. Tohiiach and T. T. Puck, J. Am. Chem. Soc, 74, bbbl (1952). 

 " signifies 0-30%o adsorption; +, 30-45%o; + + , 45-60%; + + + ,60- 

 80%; + + + + ,80-100%. 



Barry and Goebel (1951) studied the adsorption of phage to 

 cultures of phase II Sh. sonnei which had been treated in various 

 ways. The untreated bacteria adsorb T3, T4, and T7 at similar 

 rates. Different culture samples were treated with phenol, 



