determined Protocols

Category: Reporter Gene Assays: B-Galactosidase Assay Protocols

The recommended amount of RSV-ß-Galactosidase plasmid to use for transfection of cells (60 mm or 100 mm dish) is 1-2 µg. The optimal amount of plasmid DNA will be determined by the efficiency of transfection , which is very dependent upon the particular cell line and transfection protocol. - [Read B- Galactosidase Assay Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cytotoxicity Assays in Cell Culture Protocols

Human A431 cells and mouse 3T3 cells are exposed in culture to UV light both in the presence and absence of test compound.  Phototoxicity is expressed as a decrease in cell viability as determined by the MTT assay. - [Read Cell Culture Phototoxicity Test Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cytotoxicity Assays in Cell Culture Protocols

The potential cytotoxicity of compounds under hypoxic conditions is determined by exposing cell cultures to test compounds in a low oxygen atmosphere.  Subsequent cell survival is determined by the MTT and methylene blue colorimetric assays. - [Read Colorimetric Cytotoxcity Assays for Anchorage Dependent Cells Protocol]

Category: Molecular Biology Protocols: Carbohydrate Protocols

Deglycosylation steps are different with every glycoprotein and must be determined empirically (Methods in Enzymology, 1994, 230: 44-57). A typical test reaction of human transferrin is described. T.H. Plummer, Jr. and A.L. Tarentino, Department of Biochemistry, New York State Department of Health, Wadsworth Center for Laboratories and Research, Albany, New York - [Read Deglycosylation of Glycoproteins Using Endoglycosidases]

Category: Protein Protocols: Protein Quantitation Concentration Protocols

Determination of the Extinction Coefficient for a Protein of Unknown Concentration. The concentration can be determined for a solution of a pure protein with unknown extinction coefficient. - [Read Determination of the Extinction Coefficient for a Protein of Unknown Concentration]

Category: Transfection Protocols: Stable Transfection Protocols

Pulsed electrical fields can be used to introduce DNA into a wide variety of animal cells. Electroporation works well with cell lines that are refractive to other techniques, such as calcium phosphate-DNA coprecipitation. But, as with other transfection methods, the optimal conditions for electroporating DNA into untested cell lines must be determined experimentally. - [Read DNA Transfection by Electroporation]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cytotoxicity Assays in Cell Culture Protocols

Macrophage cells in culture may be exposed to particulate matter, and resultant effects upon cell viability determined by vital dye exclusion and enzyme leakage assays. - [Read Dust Toxicity in Rat Alveolar Macrophage Cultures Protocol]

Category: Cell Biology and Cell Culture: ES Stem Cell Biology and Culture: Embryotoxic Potential Testing of Chemicals

EMBRYONIC STEM CELL TEST (EST). The embryotoxic potential of chemicals is determined by the evaluation of the inhibition of differentiation of embryonic stem cells (ES) and the inhibition of growth of ES and 3T3 cells. Scientific Information Service - [Read EMBRYONIC STEM CELL TEST (EST)]

Category: Cloning Protocols

Protocol describes a method for DNA fragmentation by nebulization, in which the fine mist created by forcing a DNA solution through a small hole in the nebulizer unit is collected. The size of the fragments obtained by nebulization is determined chiefly by the speed at which the DNA solution passes through the hole, altering the pressure of the gas blowing through the nebulizer, the viscosity of the solution, and the temperature. - [Read Fragmentation of DNA by Nebulization Protocol]

Category: Microinjection Protocols: Microinjection of DNA Protocols

This protocol describes a method for constant-flow microinjection using the Pneumatic PicoPump (World Precision Instruments). This type of system is very simple and can be assembled on a relatively low budget. In this method, a constant flow of sample is delivered from the tip of the pipette, and the amount of sample injected into the cell is determined by how long the pipette remains in the cell. - [Read Gene Delivery by Direct Injection (Microinjection) Using a Controlled-Flow System Protocol]

Category: Primary Cell Isolation and Culture Protocols: Mammalian Cell Culture Protocols

Generation of a growth curve can be useful in evaluating the growth characteristics of a cell line. From a growth curve, the lag time, population doubling time, and saturation density can be determined. - [Read Generation of Growth Curve Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cell Specific Cytotoxicity Assays Protocols

The basis of this procedure is that two specific cell type preparations may be isolated, exposed separately to various compounds over a range of concentrations, and the cytotoxicity of these determined.  Parameters deemed indicative of a cytotoxic effect include a reduction in de novo protein synthesis and decreased glucose and fatty acid metabolism.  A cytotoxic effect may indicate that a chemical is likely to be nephrotoxic in vivo. - [Read Isolated Rat Glomeruli and Proximal Tubules]

Category: Cytogenetics Protocols

Karyotyping is a valuable research tool used to determine the chromosome complement within cultured cells. It is important to keep in mind that karyotypes evolve with continued culture. Because of this evolution, it is important for the interpretation of biochemical or other data, that the karyotype of a specific sub-line be determined. - [Read Karyotyping Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cytotoxicity Assays in Cell Culture Protocols

This simple cell culture-based cytotoxicity test (in which cell viability is determined by uptake of the dyes ethidium bromide and fluorescein acetate) has been developed as a general test for acute toxicity. - [Read LS-L929 Cytotoxcitiy Test]

Category: DNA Protein Interactions Protocols: Dnase Footprinting Assay Protocols

Dnase I is used to fragment a radiolabeled target DNA in the presence and absence of a nuclear extract.  A "footprint" is generated when a protein binds to the target and protects a specific segment of DNA from the nucleolytic activity of Dnase I. By comparing the electrophoretic mobility of the Dnase I cleavage products to those of a sequence ladder derived from the same DNA fragment, the position(s) of the DNA sequences recognized by DNA-binding proteins can be determined. - [Read Mapping Protein-binding Sites on DNA by Dnase I Footprinting Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cytotoxicity Assays in Cell Culture Protocols

Membrane permeability of perfused cell cultures, as determined by the efflux of [3H]-2-deoxy-D-glucose-6phosphate, is used as an indicator of the cytotoxic effect of chemicals. - [Read Membrane Permability as a Measure of Cytotoxcity in Perfused Cell Cultures]

Category: Primary Cell Isolation and Culture Protocols: Laser Capture Microdissection Protocols

Human tissues are comprised of multiple interacting cell populations in a complex three dimensional arrangement with each cellular phenotype determined by a unique profile of mRNA and protein expression. Before microdissection techniques were developed, the only analysis tools for phenotypic studies were primarily immunohistochemistry and in-situ hybridization. While useful, these tools are limited to single gene analysis and, in general, do not allow qualitative studies. - [Read Microdissection Overview]

Category: Chromatography Protocols: Dye Ligand Affinity Chromatography Protocols

Protocol describes a general method for the purification of protein using dye-ligand affinity chromatography.  The effectiveness of this protocol is dependent upon the reader having previously determined the optimal dye and buffer conditions to use for binding and eluting the protein(s) of interest. - [Read Purification of Protein Using Dye-Ligand Affinity Chromatography Protocol]

Category: Plant Biology Protocols: Plant Proteins, Peptides and Antigens

The activity of ß-glucuronidase (GUS) can be accurately determined in intact plant tissue using 4-methylumbelliferyl ß-D-glucuronide (4-MUG) as a substrate. Upon hydrolysis by GUS, the fluorochrome 4-methyl umbelliferone (4-MU) is produced. This method is based on the permeability of both 4-MUG and 4-MU through plant tissue. It consists of incubation of the tissue with the reagent and quantification of the fluorescence emitted by 4-MU in the solution. GUS activity in each sample can be... - [Read Quantitative GUS Activity Assay in Intact Plant Tissue Protocol]

Category: PCR Protocols: Quantitative PCR Protocols

Quantitative PCR involves co-amplification of two templates: a constant amount of a preparation containing the desired target sequence and serial dilutions of a reference template that is added in known amounts to a series of amplification reactions.  The concentration of the target sequence is determined by simple interpolation into a standard curve. - [Read Quantitative PCR Protocol II]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cell Specific Cytotoxicity Assays Protocols

In this test rabbit articular chondrocytes are cultured in the presence of test compound, the toxicity of which is then determined by its effect on the production of proteoglycan by the cells, as detected by the dye Alcian Blue. - [Read Rabbit Articular Chondrocyte Functional Toxicity Test]

Category: PCR Protocols: Reverse Transcriptase RT-PCR Protocols

In the first part of this protocol, the linear range of amplification is determined by carrying out 10 identical PCRs in the presence of [{alpha}-32P]dCTP and stopping one reaction after every two cycles.  Amplification products are quantified on a denaturing polyacrylamide gel and the results plotted on a graph (counts per minute vs. cycle number).  Total RNA is used as an internal control. - [Read Relative RT-PCR: Determining the Linear Range of Amplification and Optimizing the Primers:Competimer]

Category: Chromatography Protocols: Ion Exchange Chromatography Protocols

Protocol for separating proteins using ion-exchange chromatography. Protocol details the practical considerations of an ion-exchange chromatography (IEC) experiment.  The choice of what type of ion exchanger to use, as well as the composition of the buffers used in this experiment, should be determined prior to beginning this protocol. - [Read Separating Proteins Using Ion-Exchange Chromatography Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols: Cytotoxicity Assays in Cell Culture Protocols

Rabbit-derived corneal cells are cultured in the presence of test compounds, the toxicity of which are determined by their effect upon cell viability.  A decrease in cell number, as measured by uptake of the dye Neutral Red, serves as an indicator of potential cytotoxicity.  This test has been proposed as a potential replacement alternative for the Draize Eye Irritation test. - [Read SIRC Cytotoxcitiy Test]

Category: Western Blot Protocols: Immunoblot Stains for Total Protein Protocols

Protocol used to determine the position of molecular-weight markers and to ensure that efficient transfer of proteins to the blot has occurred, the total composition of the proteins can be determined by staining the membrane with Ponceau S (Staining Immunoblots for Total Protein Using Ponceau S) or India ink. - [Read Staining Immunoblots for Total Protein Using India Ink Protocol]