Abstract: The invention provides novel methods for the separation of charged molecules such as proteins according to the isoelectric points (pI's) and includes the systems and buffering compositions employed for isolating charged molecules. The invention further provides for modifications to the above described chromatographic methods that enable the separation of charged molecules exhibiting virtually identical pI's by shifting both the buffer's pKa and the pI's of the eluted charged molecules while they are traversing the ion exchange column.

Abstract: Systems and methods for separating charged molecules on the basis of their differential electrostatic binding to a charged stationary phase comprise controlling the creation of simultaneous independent or dependent pH and additive gradients.

Abstract: Systems and methods for separating charged molecules on the basis of their differential electrostatic binding to a charged stationary phase comprise controlling the creation of simultaneous independent or dependent pH and additive gradients.

Abstract: The present invention provides a new analysis based on Differential Spectral Topographic Analysis (DISTA). Using data from the spectral methods known in the art, DISTA is based upon the normalization of the spectra to a fixed topographic space, creating a set of spectral forms, and the summation of the absolute differences in topography between one or more reference spectra and the test spectra taken at different magnitudes of the perturbing parameter. This method allows for a sensitive estimate of the fraction of form A and form B of an entity of interest. This method also allows for the calculation of apparent free energy from the conversion of the entity of interest from a first to a second form where appropriate, and in the alternative, calculation of a fraction of structural changes.

Abstract: The present invention provides a new analysis based on Differential Spectral Topographic Analysis (DISTA). Using data from the spectral methods known in the art, DISTA is based upon the normalization of the spectra to a fixed topographic space, creating a set of spectral forms, and the summation of the absolute differences in topography between one or more reference spectra and the test spectra taken at different magnitudes of the perturbing parameter. This method allows for a sensitive estimate of the fraction of form A and form B of an entity of interest. This method also allows for the calculation of apparent free energy from the conversion of the entity of interest from a first to a second form where appropriate, and in the alternative, calculation of a fraction of structural changes.

Abstract: An apparatus and method for modified intrinsic state spectral analysis determines a proportion of a plurality of intrinsic structures of an optically active molecule. A spectropolarimeter generates a plurality of intrinsic spectra. Each of the plurality of intrinsic spectra is an intrinsic state vector corresponding to a plurality of intrinsic molecular structures. The spectropolarimeter also generates a spectrum for a sample of the optically active molecule. The sample spectrum is a sample state vector of the optically active molecule. A controller determines a plurality of estimate state vectors based on a plurality of perturbed intrinsic state vectors. Each of the plurality of perturbed intrinsic state vectors corresponds to a perturbed intrinsic structure. An optimum proportion of the plurality of perturbed intrinsic state vectors corresponds to each estimate state vector. The plurality estimate state vectors are matched against the sample state vector to determine a best match estimate state vector.