histidine Protocols

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Microorganism Cytotoxicity Assays Protocols

The AMES procedure evaluates the mutagenic potential of test chemicals by their effect on five histidine requiring strains of the bacterium, Salmonella typhimurium in the absence and presence of a rat liver metabolising system. - [Read Ames Test]

Category: Chromatography Protocols: Immobilized Metal Ion Affinity Chromatography Protocols

Immobilized metal ion affinity chromatography (IMAC) exploits a molecule’s affinity for chelated metal ions.  The amino acid histidine present in many proteins forms complexes with transition metal ions such as Cu2+, Zn2+, Ni2+ and Fe3+.  Chelating Sepharose™ Fast Flow with a suitable immobilized metal ion will therefore selectively retain proteins with exposed histidine. - [Read Chelating Sepharose Fast Flow Protocol]

Category: Chromatography Protocols: Immobilized Metal Ion Affinity Chromatography Protocols

Protocol for the optimization of imidazole concentrations for immobilized metal-ion affinity chromatography. Most samples from which histidine-tagged proteins are to be purified also contain endogenous protein contaminants that bind to the immobilized metal-ion affinity chromatography (IMAC) adsorbent.  Usually, these proteins bind more weakly than the histidine-tagged protein. - [Read Optimization of Imidazole Concentrations for Immobilized Metal-Ion Affinity Chromatography Protocol]

Category: Chromatography Protocols: Immobilized Metal Ion Affinity Chromatography Protocols

Protocol for the preparation of a prepacked IMAC column. Purification of histidine-tagged proteins on a milligram scale can be performed conveniently on a small (1to 5-ml) immobilized metal-ion chromatography (IMAC) column using a syringe to load the sample, wash the column, and elute the protein. - [Read Preparation of a Prepacked IMAC Column Protocol]

Category: Chromatography Protocols: Affinity Chromatography Protocols

Recombinant proteins engineered to have a polyhistidine tail at either the carboxyl or amino terminus can easily be purified in one step by affinity chromatography on a resin carrying chelated nickel ions.  Chromatography can be carried out in column or batch formats.  After unbound proteins are washed away, the target protein is eluted using imidazole, which typically preserves the antigenic and functional features of the protein. - [Read Purification of Histidine-tagged Proteins by Immobilized Ni2+ Absorption Chromatography Protocol]

Category: Chromatography Protocols: Immobilized Metal Ion Affinity Chromatography Protocols

Immobilized metal-ion affinity chromatography (IMAC) is suitable for the purification of proteins under denaturing conditions.  Either guanidine-HCl or urea can be used, although guanidine-HCl is a stronger denaturant than urea.  Proteins that have been adsorbed to the column in the presence of guanidine-binding buffer may be washed with urea-binding buffer and eluted with urea elution buffer. - [Read Purification of Histidine-Tagged Proteins under Denaturing Conditions Using IMAC Protocol]

Category: Chromatography Protocols: Immobilized Metal Ion Affinity Chromatography Protocols

Histidine-tagged proteins can be purified on prepacked 1-ml immobilized metal-ion affinity chromatography (IMAC) columns without optimization of the separation conditions.  The method allows fast capture of the target protein, although with a lower purity than can be obtained under optimized conditions. - [Read Purification of Histidine-Tagged Proteins Using IMAC Without Parameter Optimization Protocol]

Category: Yeast Cell Culture Protocols: Yeast Sporulation Protocols

Protocol for spore germination. This procedure is typically used for the isolation and preparation of spores from a diploid strain heterozygous for a marked disruption (e.g., yfg1::his3+) Inoculation of the spore population into minimal medium lacking the nutritional supplement corresponding to the disruption marker (e.g., minimal medium lacking histidine) allows only the disruption spores to germinate. - [Read Spore Germination Protocol]