The partial specific volumes of a number of proteins and polypeptides will be measured in buoyant CsCl solutions as a function of pH. The new Anton Paar densimeter will be employed to rapidly and accurately determine solution density as a function of concentration. The same technique will be employed to determine the partial specific volume of water and the specific volume of poly(Lys) and poly(His) in these solutions. These data will then be combined with the buoyant densities of these polymers which have already been measured in order to obtain accurate hydration values without any assumptions. Sequential polar-polar and polar-non-polar copolypeptides will be synthesized and their buoyant titrations measured. Block copolymers with hydrophobic centers and large ionizable ends will be prepared. Several new chemical derivations of bovine serum mercaptalbumin and ovalbumin will be made and their buoyant titration behavior contrasted with that of the native protein. The latter two investigations will yield information on inter-residue interactions in copolypeptides and the contribution of specific residues to the buoyant densities of proteins.