Malvern Zetasizer Nano Series, Accessories Manual

Page: 116 / 126

Chapter 6 Advanced protein features
Page 6-18 MAN 0487
D
H
: Hydrodynamic diameter. The diameter as measured via DLS.
D
Mass
: The diameter by mass. This is calculated from the known molecular
weight and the specific volume of the particle.
f : Particle frictional coefficient.

: Solvent viscosity.
T : Absolute temperature.
Shape estimate calculation
Enter the Molecular weight result, Specific volume and Hydrodynamic
diameter (measured using dynamic light scattering) into the appropriate text
boxes.
The Perrin (shape) factor ( F ), plus the Prolate and Oblate axial ratio will be
automatically calculated and displayed in the results area.
If required, a solvent layer can be subtracted from the hydrodynamic radius when
calculating the Perrin factor. To do this select the
Subtract solvent layer check
box.
Molecular weight estimate
Whilst the preferred method of
measuring absolute molecular weight is
by performing concentration dependent
light scattering measurements, this can
be very time consuming, from the point
of view of the sample preparation.
Providing that only an estimate of the
molecular weight is required then it can
be derived by utilising a relationship
between the Hydrodynamic diameter
and the molecule conformation.