Sedimentation coefficient-molecular weight relationship

D. Polymolecularity Correction Factors for Sedimentation Coefficient versus Molecular Weight Relationship Table 20. For Sw, Afw and SZ and LN... 

Sedimentation Coefficient versus Molecular Weight Relationship VII / 227... 

D. SEDIMENTATION COEFFICIENT VERSUS MOLECULAR WEIGHT RELATIONSHIP... 

Sedimentation velocities of DNAs can be determined as described by Prunell and Ber-nardi (1973), and molecular weights then calculated from the sedimentation coefficients 20,w, using the relationship of Eigner and Doty (1965)... 

The exponent rule is especially significant in combination with the rule that states that the relationships between two variables can always, at least over a limited range of values, be written as an exponential relationship. It has been found empirically that over wide ranges of the molar mass the following relationships between the molecular weight and the sedimentation coefficient 5, the diffusion coefficient D, or the intrinsic viscosity [17] are valid ... 

TABLE 1. Relationship Between Sedimentation Coefficients and Molecular Weight of Complexes and their D-RNA. 

Also evident from the above two plots should be the fact that frictional coefficient and molecular weight are very related functions. Thus any study to find out the relationship between s and M. in fact, becomes a study to find out the relationsffip between frlction d coefficient and molecular weight. Such studies become especially Important since many of the researchers prefer to characterize a macromolecule by just finding out its sedimentation coefficient and not its molecular weight. This is done because it is simpler to determine the former. The sedimentation coefficient is then supposed to reflect the molecular weight of the macromolecule. 

Although the relationship exists, it is not very good to calculate the molecular weight from sedimentation coefficient values. This is so since a small error in the measurement of sedimentation coefficient can be amplified and a value of molecular wei t so obtained will be off significantly. 

Correspondingly, polymolecularity correction factors are useful for the relationship of sedimentation coefficient versus molecular weight,... 

---