membrane Protocols

Category: Primary Cell Isolation and Culture Protocols: Laser Capture Microdissection Protocols: Tissue Preparation for LCM Protocols

LCM isolates specific cells or tissues from samples mounted on microscope slides. The samples are viewed through a thermoplastic film that is attached to a microcentrifuge tube lid. Localized heat, caused by the application of a laser pulse, fuses the membrane to the cells of interest, which can then be harvested for further analysis. RNA and proteins can be purified from the isolated cells, allowing detailed analysis of gene expression. This protocol is divided into three stages. - [Read (LCM): Preparation and Sectioning of Frozen Tissue Blocks and Purification of RNA from Isolated Cel]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols

Protocol describes systems in which the membranes are allowed to float through a density gradient from a dense load zone. This is an ideal format. - [Read A Self-generated Gradient to Discriminate a Cytosolic or Membrane Location of Large Protein Complex]

Category: Protein Protocols: Protein Trafficking

Protocol is based on methods for the resolution of GLUT4 containing vesicles and the identification of phosphoinositide kinase containing vesicles in 3T3-L1 adipocytes. They may have a wider application to any low-medium density membranes. Protocol incorporates the strategy of using a low density microsome fraction as the gradient input, commonly used in GLUT 4 studies that may have a wider application to other investigations. - [Read Analysis of Membrane Trafficking and Intracellular Signaling in Self-Generated Iodixanol Gradients]

Category: Cell Organelle Protocols: Mitochondria Protocols

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]

Category: Cell Biology and Cell Culture: Flow Cytometry Protocols: Apoptosis Cytometry Protocols

Annexin V, belonging to a recently discovered family of proteins, the annexins, with anticoagulant properties has proven to be a useful tool in detecting apoptotic cells since it preferentially binds to negatively charged phospholipids like PS in the presence of Ca2+ and shows minimal binding to phosphatidylcholine and sphingomyeline. Changes in PS asymmetry, which is analyzed by measuring Annexin V binding to the cell membrane, were detected before morphological changes associated with... - [Read Annexin V Protocol]

Category: Cell Biology and Cell Culture

This chemotaxis assay protocol is based on the premise of creating a gradient of the chemotactic agent and allowing cells to migrate through a membrane towards the chemotactic agent. A chemotaxis assay can determine whether your protein or small molecule of interest has chemotactic activity on a specific cell type. Chemotaxis is then the ability of a protein to direct the migration of a specific cell. - [Read Chemotaxis Assay Protocol]

Category: Pharmacology and Toxicology Protocols: Cytotoxicity Protocols

Protocol describes automation of the CytoTox-ONE Homogeneous Membrane Integrity Assay. - [Read CytoTox-ONE Homogeneous Membrane Integrity Assay Protocol]

Category: Cell Organelle Protocols: Mitochondria Protocols

Protocol for the detection of changes in mitochondrial membrane potential on the FACSCalibur. - [Read Detection of Changes in Mitochondrial Membrane Potential on the FACSCalibur]

Category: Cell Biology and Cell Culture: Apoptosis Protocols: Apoptosis Analysis

Detection of Phosphatidylserine Externalization During Apoptosis. Shailaja Kasibhatla et al. An early event in apoptosis is the externalization of phosphatidylserine (PS), a phospholipid normally restricted to the inner leaflet of the plasma membrane. This apoptotic event can be monitored using Annexin V, a PS-specific binding protein. This protocol uses Annexin V-FITC as a probe, but Annexin V-biotin is also available, and binding can be revealed using streptavidin-FITC or oth - [Read Detection Of Phosphatidylserine Externalization During Apoptosis (Subscription Required)]

Category: Xenopus Protocols: Xenopus Injection Protocols

Differences in injection of X. laevis and X. tropicalis. Includes: X. tropicalis lays eggs about 4 hours after a boost of hCG; In vitro fertilization is not nearly as efficient in trops compared to laevis; X. tropicalis embryos are much softer than X. laevis embryos; X. tropicalis embryos whose jelly coats are removed by cysteine have a loose sticky vitelline membrane; X. tropicalis do not have a "summer slump". - [Read Differences in Injection of X. laevis and X. tropicalis]

Category: DNA Protocols: DNA Extraction Protocols: Agarose Gel DNA Extraction Protocols

DNA Extraction from Agarose Gels Protocol. The page includes cutting out the DNA band from the gel, and describes three methods including 1) Spin-columns (Nucleic acid purification columns), 2) using Dialysis tubing (semi-permeable membrane, Visking tubing), and the 3) Paper strip method.Matt Lewis, Department of Pathology, University of Liverpool. - [Read DNA Extraction from Agarose Gels Protocol]

Category: Nucleic Acid Detection Protocols: Nucleic Acid Blotting Protocols

Protocol for dot and slot hybridization of purified RNA. Dot blotting of RNA is best carried out using purified preparations of RNA that are denatured with glyoxal or formaldehyde immediately before loading onto a nylon membrane through a vacuum manifold. - [Read Dot and Slot Hybridization of Purified RNA Protocol]

Category: Cell Biology and Cell Culture: Flow Cytometry Protocols

FIXATION and DNA Staining for Cell Cycle Analysis Protocol. This method of DNA staining utilizes ethanol to fix the cells and permeabilize the membrane, which allows the dye (Propidium Iodide) to enter the cells.  Propidium Iodide (PI) is a DNA-binding fluorochrome that intercalates in the double-helix.  Ribonuclease-A is used to eliminate the staining of double-stranded RNA. - [Read FIXATION and DNA Staining for Cell Cycle Analysis]

Category: Cell Organelle Protocols: Mitochondria Protocols

Protocol describes a method for evaluation of mitochondrial function using the fluorochrome CMXRos. CMXRos is sequestered by actively respiring mitochondria, but washed out when the mitochondrial membrane potential is lost. This analysis can be combined with the TUNEL technique or immunocytochemistry. - [Read Flow Cytometric Analysis of Mitochondrial Transmembrane Potential ({Delta}{Psi}m)]

Category: Microscopy Protocols

FM 4-64 is a lipophilic styryl dye and a vital stain: it fluoresces only in living cells, so cells cannot be fixed then stained nor stained then fixed. You must stain and observe living cells. FM 4-64 does not permeate cell membranes but, instead, intercalates into the plasma membrane is then taken into the cells by endocytosis. - [Read FM 4-64 Labeling of Yeast Vacuole Membranes Protocol]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Membrane Isolation Protocols

The protocol described in this protocol has been used principally for analyzing the Golgi, endoplasmic reticulum and trans-Golgi network but markers for other compartments (e.g. ERGIC and endosomes) have also been analyzed. Modifications either to the gradient density range or the centrifugation conditions influence the ability of the gradient to resolve multiple compartments. - [Read Fractionation of Golgi, ER, TGN and Other Membrane Compartments in Pre-Formed Iodixanol Gradients]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Mitochondria Isolation Protocols

Generally in iodixanol gradients the density of organelles decreases in the series: peroxisomes, mitochondria, lysosomes, ER, Golgi, although in Dictyostelium discoideum, the lysosomes are denser than the mitochondria. Iodixanol gradients can usually provide satisfactory resolution of all these membrane particles although it may be necessary to modulate either the gradient or centrifugation parameters in order to optimize a particular separation. - [Read Fractionation of Mitochondria, Lysosomes, Peroxisomes, ER and Golgi in Pre-formed Iodixanol Gradient]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Membrane Isolation Protocols

This protocol is concerned with the use of iodixanol gradients in an analytical mode to study the membrane localization of a particular protein or function. Continuous gradients are best suited to this task. One of the protocols described in this protocol starts with a discontinuous gradient, but since the gradient is centrifuged at 174,000g for 16 h it will become continuous by diffusion. - [Read Fractionation of Yeast Membranes in Pre-Formed Continuous Iodixanol Gradients]

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

Accumulation of lipophilic substances in the plasma membrane may affect the membrane lipid order and consequently affect the function of these proteins.  Changes in the activity of the Na+/K+ -ATPase, which is the major active transport system responsible for the electrochemical potential in mammalian cells, can therefore be an indication of the effect that a chemical may have on the viability of the cell membrane and possibly the whole cell. - [Read Hamster Ovary Cell NA+/K+ -ATPase Test]

Category: Microscopy Protocols: Live-Cell Imaging Protocols

Using confocal laser-scanning microscope & GFP fusion proteins in time-lapse imaging to visualize the behavior of organelles and to track membrane-bound transport intermediates that bud off from organelles. Practical issues related to construction & expression of GFP fusion proteins are discussed. Essential for optimizing the brightness and expression levels of GFP fusion proteins so that intracellular membrane-bound structures containing these fusion proteins can be readily visualized. - [Read Imaging of Organelle Membrane Systems and Membrane Traffic in Living Cells]

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

Protocol for Immunoblot. Includes: Staining and Laser Capture Microdissection; Protein Separation by Polyacrylamide Gel Electrophoresis; Electrophoretic Transfer To a Membrane (Nylon, PVDF or Nitrocellulose); Primary and Secondary Antibody Incubations; Visualization. - [Read Immunoblot Protocol]

Category: Western Blot Protocols: Antigen Detection Methods Protocols

The blot is blocked to prevent nonspecific adsorption of the immunological reagents.  Antibodies are then bound to the proteins immobilized on the membrane, and the antigen is detected by labeling the antibodies with conveniently identified tags.  Common labeling methods for chemiluminescent detection include anti-immunoglobulin antibody-coupled enzymes such as horseradish peroxidase, which catalyzes the oxidation of luminol and in turn releases light. - [Read Immunoblotting: Antigen Detection Using Chemiluminescence Protocol]

Category: Western Blot Protocols: Antigen Detection Methods Protocols

The blot is blocked to prevent nonspecific adsorption of the immunological reagents.  Antibodies are then bound to the proteins immobilized on the membrane, and the antigen is detected by labeling the antibodies with conveniently identified tags. - [Read Immunoblotting: Antigen Detection Using Chromogenic Methods Protocol]

Category: Western Blot Protocols: General Western Blot Methods Protocols

The transfer of proteins from a Tris/glycine SDS-polyacrylamide gel to a membrane using a semi-dry method is achieved by placing the gel next to a piece of nitrocellulose filter.  This sandwich is placed directly between two plate electrodes, and the proteins are then transferred from the gel onto the filter. - [Read Immunoblotting: Semi-Dry Electrophoretic Transfer of Proteins from Gels to Membranes Protocol]

Category: Western Blot Protocols: General Western Blot Methods Protocols

Transfer of proteins from a Tris/glycine SDS-polyacrylamide gel to a membrane using the submerged method is achieved by placing the gel next to a piece of nitrocellulose filter, submerging this sandwich in a large volume of transfer buffer in a transfer tank, and running current from one side of the transfer tank to another.  The proteins are then eluted by transferring them from the gel onto the filter. - [Read Immunoblotting: Submerged Electrophoretic Transfer of Proteins from Gels to Membranes Protocol]