TABLE 1.

Chemical compositions of S. Typhi Vi-DT conjugates

ConjugateAH/DTVi concn (μg/ml)Yielda (Vi, %)Vi/DT ratio (wt/wt)Vi repeating units/DTb
% (wt/wt)Molar ratiob
C13.51258.05420.80198
C23.11153.83481.06263
C33.21147.00c0.87216
C42.91050.77440.91226
C53.41256.04521.09270
  • a Yield was based on the recovery of Vi.

  • b Molar ratio calculated based on the following: DT, Mr = 62,000; Vi repeating unit, Mr = 250; ADH, Mr = 174.

  • c The accidental loss of some material prevented accurate determination of the yield.