Bio-rad Laboratories, Inc.

Lee Olech

Cory Panattoni

Thomas R Berkelman

Xuemei Yang

Shane Petersen

Craig Rowell

Sean Cater

Hong Chen

Jiali Liao

Xuemei He

Russell Frost

Christopher Belisle

Mingde Zhu

William Strong

Clayton T McKee

Tom R Berkelman

Adriana Jeanne Harbers

Praveena D Garimella

Clayton T Mckee

Garimella Praveena

A method for manufacturing a mixed-mode chromatography medium is provided. The method can include, for example, oxidizing diol groups on diol-functionalized solid particles having pores of a median diameter of 0.5 micron or greater with substantially no pores of 0.1 micron or less in diameter and having a diol density of from about 200 to about 300 &#x3bc;mol/mL to aldehyde groups, thereby converting said diol-functionalized solid particles to aldehyde-functionalized solid particles; and coupling amine-functionalized ligands to said aldehyde-functionalized solid particles, said amine-functionalized ligands comprising an amine-substituted hydrophobic group joined to an acid moiety selected from the group consisting of a carboxyl group and a sulfo group.

Solid phase for mixed-mode chromatographic purification of proteins

Proteins are purified by a mixed-mode chromatography system formed by attaching a ligand comprising benzamidoacetic acid to a large-pore support matrix, the only linkage between the ligand and the support matrix being a chain having a backbone of no more than three atoms between a phenyl ring and the support matrix.

Polyacrylamide gels that offer high resolution in protein separations and are more stable relative to hydrolysis than conventional polyacrylamide gels that rely on Tris or Tris-Bis as buffering agents are made by incorporating triethanolamine in place of most or all of the Tris or Tris-Bis.

Hydrolysis-resistant polyacrylamide gels

Proteins are purified by a mixed-mode chromatography system formed by attaching a ligand with cation exchange and hydrophobic functionalities to a large-pore support matrix, the only linkage between the ligand and the support matrix being a chain having a backbone of no more than three atoms between the hydrophobic group and the support matrix.

A method is provided for detecting a protein using a cyclodextrin covalently linked to at least one label. The cyclodextrin can associate with the protein by sequestering an aromatic amino acid side-chain of the protein in its hydrophobic cavity. After contacting the protein with the cyclodextrin, the label can be detected directly or can undergo a chemical interaction with a reagent to form a detectable product. The label can include an indole moiety, which can react with a halo-substituted organic compound upon exposure to UV light and thereby be rendered fluorescent. Alternatively, the label can include a biotin moiety, which can bind to a binding partner such as avidin, or variants thereof, to form a detectable molecular complex. A labeled cyclodextrin can be used in the present methods to detect a protein of interest in an electrophoresis gel or on a blotting membrane. Aromatic amino acid residues of the protein, in particular tryptophan, remain protected from chemical modification due to sequestration by the cyclodextrin, making these methods compatible with downstream applications that require intact protein. Also provided herein are compositions, kits, and electrophoresis gels for use in detecting proteins.

Protein detection using modified cyclodextrins

Colloidal formulation for staining proteins and methods of their use are provided.

Colloidal Coomassie stain

The proteins in a biological sample that is sought to be analyzed for its protein composition by an electrophoretic or chromatographic procedure are coupled to a dye in an unusually efficient manner by combining the sample with a solid dry composition containing the dye, a buffering agent, and in preferred embodiments, a denaturing agent as well. The solid and dry form of the composition prevents the dye from deteriorating or decomposing, and the combination of components in the composition allows the dye to couple to the proteins in a relatively uniform manner with no overstaining of the protein when the composition and the sample are heated together and held at an elevated temperature for a short period of time.

Labeling proteins with dyes that are insoluble or only sparingly soluble in water

In pre-cast slab gel cassettes, the formation of pathways in which proteins can migrate between the gel and the walls of the cassette to form shadow bands is avoided by the application of a coating of a nonionic amphiphilic polymer to the cassette walls. The coating also prevents the gel from sticking to the walls when the gel is to be removed from the cassette after electrophoresis.

Coating of pre-cast electrophoresis slab gels

Carboxylic acid-substituted polyalkylene polyamines in which amine nitrogen atoms on the polyamine backbone structure are replaced by guanidine groups provide a pH range extending into high pH values. These substances are useful as carrier ampholytes in isoelectric focusing.

Carrier ampholytes of high pH range

Immobilized pH gradient (IPG) strips are encapsulated in an enclosure that seals the strip from atmospheric exposure and yet contains sufficient volumetric capacity to accommodate the strip in rehydrated form. The enclosure contains a pair of electrode access apertures each of which is spanned by a dialysis membrane to permit electrical contact between external electrodes and the encapsulated IPG strip, and one or more sample application apertures through which liquid sample can be applied to the strip. Each of the apertures is covered by a protective cover or flap that is removable to expose the aperture.

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Pinole, CA, United States of America

Lee Olech