Traditional animal models to quantify the degree of blood vessel formation are being replaced by cell culture assays
that are easier to set up, statistically reliable and can be automated in a drug screening laboratory. These assays rely on the endothelial cells’ ability to form distinct blood-vessel-like tubules in an extracellular matrix where they can subsequently be visualized by fluorescence microscopy. - [Read An Image-Based Assay of Endothelial Cell Tube Formation as a Model of Angiogenesis]
The technique of JC-1 staining has been developed with the intent to detect DY in intact, viable cells. For this purpose JC-1 acts as a marker of mitochondrial activity, since the formation of J-aggregates, which give red emission, is reversible. Cells with high DY are those forming J-aggregates, thus showing high red fluorescence. On the other hand, cells with low DY are those in which JC-1 maintains (or re-acquire) monomeric form, thus showing only green fluorescence. - [Read Analysis of Mitochondrial Membrane Potential with the Sensitive Fluorescent Probe JC-1]
Antibody-antigen complexes are removed from solution by addition of an insoluble form of an antibody binding protein such as Protein A, Protein G or second antibody. Immunoprecipitation protocols / methodology and technical background information. P.J. Ha - [Read Analysis of Proteins by Immunoprecipitation]
This assay is used when working with phage vectors carrying the beta-gal gene. If the cloning event disrupts a normally functional copy of the gene in the vector the resulting plaques would appear clear in the assay. If the phages contain a functional beta-gal gene they will form blue rings around their plaques. Any strain which is not an overproducer of beta-gal will work as indicator host bacteria; a single chromosomal copy of the gene is not a problem. - [Read Assay for Phage Containing the Beta-galactosidase Gene]
This assay is used when working with phage vectors carrying the beta-galactosidase gene (often used for immunological screening). If the cloning event disrupts a normally functional copy of the gene in the vector the resulting plaques would appear clear in the assay. If the phages contain a functional beta-galactosidase gene they will form blue rings around their plaques. Any strain which is not an overproducer of beta- galactosidase will work as indicator host bacteria. - [Read Assay for Phage Containing the Beta-galactosidase Gene Protocol]
This protocol describes a method to assess concentrations of free cytoplasmic calcium, [Ca2+]i, in cultured adherent RAW 264.7 cells, using a 96-well plate format. This objective is accomplished by using the Ca2+-sensitive fluorescent dye, fluo-3, which permeates cell membranes as an ester and is
hydrolyzed in the cell to its Ca2+-sensitive acidic form. - [Read Assay of Intracellular Free Calcium in RAW 264.7 Cells]
This protocol describes a method to assess concentrations of free cytoplasmic calcium (Ca2+) in cultured RAW 264.7 cells. This objective is accomplished with the Ca2+-sensitive fluorescent dye, fluo-3, which permeates cells as an ester and is hydrolyzed in the cell to its Ca2+-sensitive acidic form. Fluorescence is measured over time with adherent cells that have been washed free of extracellular dye. - [Read Assay of Intracellular Free Calcium in RAW 264.7 Cells for Ligand Screen Protocol]
This protocol describes a method to assess concentrations of free cytoplasmic calcium, [Ca2+]i, in cultured adherent RAW 264.7 cells, using a 96- well plate format. This objective is accomplished by using the Ca2+-sensitive fluorescent dye, fluo-3, which permeates cell membranes as an ester and is
hydrolyzed in the cell to its Ca2+-sensitive acidic form. Fluorescence for the adherent cells is measured over time by using a bottom read of a 96-well plate, with cells that have been washed. - [Read Assay of Intracellular Free Calcium in RAW 264.7 Cells Loaded with Fluo-3 Protocol]
This protocol describes a method to assess concentrations of free cytoplasmic calcium, [Ca2+], in cultured adherent RAW 264.7 cells, using a 96-well plate format. This objective is accomplished by using the Ca2+-sensitive fluorescent dye, fura-2, which permeates cell membranes as an ester and is
hydrolyzed in the cell to its Ca2+-sensitive acidic form. - [Read Assay of Intracellular Free Calcium in RAW 264.7 Cells Loaded with Fura-2 (with FLEXstation)]
This protocol describes a method to assess concentrations of free cytoplasmic calcium, [Ca2+]i , in cultured adherent RAW 264.7 cells, using a 96- well plate format. This objective is accomplished by using the Ca2+-sensitive fluorescent dye, fura-2, which permeates cell membranes as an ester and is
hydrolyzed in the cell to its Ca2+-sensitive acidic form. - [Read Assay of Intracellular Free Calcium in RAW 264.7 Cells Loaded with Fura-2 Protocol]
This protocol describes a method to assess concentrations of free cytoplasmic calcium (Ca2+) in mouse splenic B cells in the absence and presence of ligands for cell surface receptors. This objective is accomplished with the Ca2+-sensitive fluorescent dye, Fluo-3, which permeates cells as an ester and is hydrolyzed in the cell to its Ca2+ sensitive acidic form. - [Read Assay of Intracellular Free Calcium in Suspended B Cells]
This protocol describes a method to assess concentrations of free cytoplasmic calcium (Ca2+) in mouse splenic B cells in the absence and presence of ligands for cell surface receptors. This objective is accomplished with the Ca2+-sensitive fluorescent dye, Fluo-3, which permeates cells as an ester and is hydrolyzed in the cell to its Ca2+- sensitive acidic form. - [Read Assay of Intracellular Free Calcium in Suspended B Cells Protocol]
This protocol describes a method to assess concentrations of free cytoplasmic calcium (Ca2+) in mouse splenic B cells in the absence and presence of ligands for cell surface receptors. This objective is accomplished with the Ca2+-sensitive fluorescent dye, Fluo-3, which permeates cells as an ester and is hydrolyzed in the cell to its Ca2+-
sensitive acidic form. - [Read Assay of Intracellular Free Calcium in Suspended B Cells Protocol]
Protocol describes here a high sensitivity indirect detection procedure for DIG-labeled hybridization probes. The procedure uses the components of the HNPP Fluorescent Detection Set to form a fluorescent precipitate of HNPP (2-hydroxy-3-naphthoic acid-2’-phenylanilide phosphate) and Fast Red TR at the site of hybridization. Includes: In situ hybridization with DIG-labeled probes; Detection of DIG-labeled probes; Fluorescence microscopy. - [Read DNA In Situ Hybridization with an Alkaline Phosphatase-Based Fluorescent Detection System]
Protocol describes a high sensitivity indirect detection procedure for DIG-labeled hybridization probes. The procedure uses the components of the HNPP Fluorescent Detection Set to form a fluorescent precipitate of HNPP (2-hydroxy-3-naphthoic acid-2’-phenylanilide phosphate) and Fast Red TR at the site of hybridization. This procedure can be used to detect single copy sequences as small as 1 kb on human metaphase chromosomes. - [Read DNA In Situ Hybridization with an Alkaline Phosphatase-Based Fluorescent Detection System Protocol]
This protocol has been used successfully to 15N or 13C/15N label our proteins using our pET1120/BL21(DE3) expression system: Preparing M9 minimal media begins with preparing a 5x stock solution of M9 salts. Generally, M9 salts contain a nitrogen source in the form of NH4Cl. Since we want to add a labeled nitrogen source, our 5x salts are prepared minus NH4Cl. Standard 5 X M9 Minimal Media salts minus nitrogen source For 1L 5xM9 salts: - [Read Expression Protocol in M9 Minimal Media via T7 Promoter]
The double-stranded DNA of recombinant plasmid, phagemid, or bacteriophage M13 replicative form DNA is digested with two restriction enzymes whose sites of cleavage both lie between one end of the target DNA and the binding site for universal primer. The enzyme that cleaves nearer the target sequence must generate either a blunt end or a recessed 3' terminus; the other enzyme must generate a four-nucleotide protruding 3' terminus. - [Read Generation of Sets of Nested Deletion Mutants with Exonuclease III Protocol]
Gram-positive and Gram-negative organisms form a complex of crystal violet and iodine within the bacterial cell during the Gram-staining procedure. Gm+ organisms are thought to resist decolorization by alcohol or acetone because cell wall permeability is markedly decreased when it is dehydrated by these solvents. Thus, the dye complex is entrapped within the cell, resist being washed out by the solvents, and Gm+ bacteria remain purple following this differential stain. - [Read Gram Staining Protocol]
Protocol describes an assay that relies on the endothelial cells’ ability to form distinct blood-vessel-like tubules in an extracellular matrix where they can subsequently be visualized by fluorescence microscopy. Although quantification of the tubules can be performed by manual tracing, this method precludes the use of the assay in unbiased high-throughput applications. - [Read Image Based Assay of Endothelial Cell Tube Formation Protocol]
Positron emission tomography (PET) is a established quantitative and noninvasive imaging modality. With the PET reporter gene (PRG)/PET reporter probe (PRP) system, based on a mutant form of herpes simplex virus 1 thymidine kinase (HSV1-sr39tk), the PET signal is directly proportional to the enzymatic activity of sr39TK9-14. In this protocol, we describe in detail a method for reporter gene labeling of islets and quantitative scanning using a reporter probe. - [Read In Vivo Functional Real-Time Imaging of Transplanted Islets Using Positron Emission Tomography (PET)]
Mature Tetrahymena cells of opposite mating types are starved under appropriate salt conditions. The mating types are then combined to costimulate through cell-cell interaction. Loose pairs and then firm, irreversible pairs of cells of opposite mating types form. This method consistently results in a high percentage of pairing (usually greater than 80%) and good synchrony. - [Read Induction of Conjugation in Tetrahymena Protocol]
Mononuclear phagocyte progenitor cells derived from femoral and tibial bone marrow are propagated in the presence of M-CSF. This macrophage growth factor is secreted by L929 cells and is used in the form of L929 cell conditioned medium. The progenitor cells proliferate and differentiate through monoblast, promonocyte and monocyte stages before maturing to macrophages. At this time the cells become firmly adherent to the culture vessel. - [Read Isolation and Culture of Mouse Bone Marrow-Derived Macrophages Protocol]
A Single Stranded Plasmid DNA Isolation Protocol describing the production and isolation of single-stranded DNA (ssDNA) using bacteriophagemid-containing bacteria and helper phage. Infection of the host cells with helper phage allows for packaging of ssDNA into bacteriophage. The ssDNA can then be isolated from phage particles.
DNA microarrays are an ordered arrangement of DNA molecules complementary to genes of interest that are "spotted" by robotic equipment onto a glass slide substrate. The expression of genes in cells can be monitored with microarrays by preparing cDNA from the mRNA of cells of interest and measuring the hybridization to the microarray. This protocol describes the labeling of genomic DNA for use as a probe for hybridization to the cDNA spotted on the array.
Tubulin is polymerized into microtubules by incubating tubulin at 37°C with GTP. A nucleation seed is added when the purpose is to assay microtubule elongation. Tubulin can also be polymerized for the purposes of recycling the tubulin or labeling the microtubules with fluorescently labeled tubulin. Based on the protocol by Timothy Mitchison of Harvard University.
This Microarray Protocol Preparation of Fluorescent DNA Probes from Human mRNA protocol describes the production of probes labeled with the fluorescent dyes, Cy3 and Cy5, following the synthesis of cDNA from human mRNA and the hybridization of the probes to DNA microarrays.
A single step RNA isolation protocol using Phenol Chloroform Extraction and Acid Guanidinium Thiocyanate. This RNA isolation method uses the fact that guanidinium thiocyanate can simultaneously lyse the cells and inactive cellular RNAses during the initial RNA isolation step allow a single step in the method.
Paraffin Embedding Protocol for molecular profiling. This Paraffin Embedding Protocol describes the processing of the tissues into sections following ethanol fixation. Molecular profiling (MP) is a technique that is used to visualize the global patterns of RNA expression or protein expression in various cell types and disease processes.