Abstract:
In some aspects, an apparatus for controlling pH and/or ionic strength in a vessel is provided, In some embodiments, the apparatus comprises, a vessel in fluid communication with a first side chamber and a second side chamber, wherein the vessel does not comprise an electrode; the first side chamber divided from the vessel by an anion selective membrane or a cation selective membrane, and the first side chamber comprising an electrode; and the second side chamber divided from the vessel by a membrane, the second vessel comprising an electrode, wherein the electrode of the first side chamber and the electrode of the second side chamber are capable of forming a circuit connected via a solution, when present, in the vessel and the first and second side chambers.
Abstract:
Methods and devices for detecting and collection analytes fractionated based on pI, separating analytes via electrophoresis and pI, and purifying a target molecule using pI focusing and subsequent crystallization are provided.
Abstract:
Phosphorylated peptides are extracted from digests of biological liquids and other peptide mixtures by fractionation on ceramic hydroxyapatite. The ceramic hydroxyapatite is readily usable in a centrifuge, allowing for rapid fractionations of a large number of small volume samples, and accordingly high throughput.
Abstract:
Disclosed herein are methods of protein quantification and normalization using haloalkylated tryptophan fluorescence. Complex protein samples, i.e., samples that each contain 1,000 or more distinct proteins, from diverse sources that do not have common protein profiles are treated with a halo-substituted organic compound (i.e. haloalkane) that reacts with tryptophan residues to form fluorescent products. Irradiation of the samples with ultraviolet light and the detection and quantification of the resultant fluorescent emissions from all proteins in each sample are then used to obtain comparative values for total protein content among the various samples. The values thus obtained are found to be valid indications of comparative total protein content, despite the fact that the tryptophan levels vary widely among the various proteins in any single sample and the samples, due to the diversity of their origins, tend to differ among themselves in the identities and relative amounts of the proteins that they contain. Protein samples are also normalized to correct for differences in sample dilution, sample loading, and protein transfer inconsistencies, by using stain-free detection of total protein in each of the samples, or detection of subsamples within each sample.
Abstract:
Disclosed herein are methods of protein quantification and normalization using haloalkylated tryptophan fluorescence. Complex protein samples, i.e., samples that each contain 1,000 or more distinct proteins, from diverse sources that do not have common protein profiles are treated with a halo-substituted organic compound (i.e. haloalkane) that reacts with tryptophan residues to form fluorescent products. Irradiation of the samples with ultraviolet light and the detection and quantification of the resultant fluorescent emissions from all proteins in each sample are then used to obtain comparative values for total protein content among the various samples. The values thus obtained are found to be valid indications of comparative total protein content, despite the fact that the tryptophan levels vary widely among the various proteins in any single sample and the samples, due to the diversity of their origins, tend to differ among themselves in the identities and relative amounts of the proteins that they contain. Protein samples are also normalized to correct for differences in sample dilution, sample loading, and protein transfer inconsistencies, by using stain-free detection of total protein in each of the samples, or detection of subsamples within each sample.
Abstract:
Aspects of the invention are described throughout this document. In some embodiments, an apparatus is provided. In some embodiments, the apparatus comprises: a chamber divided into a first sub-chamber and a second sub-chamber by a dividing membrane, wherein the dividing membrane blocks or substantially blocks flow of fluid between the first and second sub-chamber; and wherein the first sub-chamber is in electrical communication with a first electrode; the second sub-chamber is in electrical communication with a second electrode; the first sub-chamber is in fluid communication with a first ion injector/extractor; the second sub-chamber is in fluid communication with a second ion injector/extractor; and and the second sub-chamber comprises an outlet.