The first part of the isolation procedure is a flotation through a continuous iodixanol gradient; this gradient is essentially a resolving gradient in which the caveolin-rich vesicles are concentrated in the top third of the gradient, while the predominantly caveolin-poor vesicles band in denser regions. A second discontinuous gradient is essentially a concentration gradient to band the caveolin-rich vesicles sharply at an interface. - [Read Purification of Caveolae Membranes from a Plasma Membrane Fraction of Cultured Cells and Tissues]
Protocol for the isolation of the lipid-rich microdomains of the plasma membrane, notably caveolae and lipid rafts. Methods for the isolation of lipid rafts are based on the insolubility of these structures in the nonionic detergent TritonX-100. Either the intact cells are treated with a detergent-containing solution or a post-nuclear supernatant is prepared from a cell homogenate and then Triton X-100 is added to this supernatant. - [Read S20 Purification of detergent-insoluble lipid rafts from cells and tissues.]
Protocol describes the first stages of Southern blotting: digestion of genomic DNA with one or more restriction enzymes, separation of the resulting fragments by electrophoresis through an agarose gel, and transfer of the denatured fragments to a membrane by downward capillary transfer. - [Read Southern Blotting: Capillary Transfer of DNA to Membranes Protocol]
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]
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 . - [Read Staining Immunoblots for Total Protein Using Ponceau S Protocol]
Protocol for the transformation of Aspergillus niger. This procedure is done by first digesting the outer cell wall, forming protoplasts, and then by making holes in the membrane
through which the dna can enter using calcium chloride and polyethylene glycol. Includes: Protocol for making A.niger protoplasts; Transformation; Plating. - [Read Transformation of Aspergillus niger Protocol]
Transient transfection into 293T cells is a convenient way to overexpress and obtain both cellular and extracellular (secreted or membrane) proteins. 293 is a human renal epithelial cell line which is transformed by adenovirus E1A gene product. 293T is a derivative which also express SV40 large T antigen, allowing episomal replication of plasmids containing the SV40 origin and early promoter region. They (both) have the unusual property of being highly transfectable. - [Read Transient Transfection Into 293T Cells Protocol]
TransWell Chemotaxis protocol. trans-well chemotaxis method from bioprotocol. The protocol is a method for studying migration towards a concentration gradient of chemoattractant of leukocytes (neutrophils, monocytes and lymphocytes) or other migratory cells. An upper chamber containing a suspension of cells is separated by a membrane from a lower chamber containing medium with chemoattractant. Chemotaxis of the cells from the upper chamber into the lower chamber can be quantified. - [Read TransWell Chemotaxis Protocol.]
The cytotoxic effect of test chemicals in V79 cell culture can be determined by assessing damage to the plasma membrane as determined by a nucleic acid leakage assay. - [Read V79 Cytotoxicity Test for Membrane Damage]
Streaking of Western Blots, Weak Bands or Weak Staining of Western Blots, Poor Transfer of Membranes, Dirty Blot, Multiple Bands on Western Blot Membrane and Film. Western Blot Info. - [Read Western Blot Troubleshooting]
The technique of patch clamp recording was invented by Bert Sakmann and Erwin Neher in 1981 for which they received the NOBEL prize. The technique is best suited for the study of the behaviour of single ion channels, or macroscopic currents in small cells or macro-patches. The whole cell technique allows one to control the composition of solutes on both sides of the membrane. - [Read Whole Cell Patch Clamp Technique]
Plasma membranes are isolated from the yeast Saccharomyces cerevisiae. The cell wall is initially digested by helicase, followed by hypoosmotic lysis and homogenization. Membranes are prepared by subsequent differential centrifugation. The activity of the H+-ATPase is then determined by measuring the amount of inorganic phosphate released from ATP. - [Read Yeast Plasma Membrane H+ -ATPASE Toxcity Test Protocol]
Accumulation of lipophilic substances, many of which may be environmental chemicals, affects the membrane lipid order and consequently affects the functions of these proteins. Since, the function of important cellular proteins, such as the H+-ATPase strongly depends upon the integrity of the lipid bilayer, the activity of the H+-ATPase may be used as a sensitive indicator of the effect that a chemical may have on the viability of the cell. - [Read Yeast Plasma Membrane H+ -ATPASE Toxicity Test]
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.
This protocol a protocol on how to generate transfected embryonic stem (ES) cell clones. The previous protocol in this series is the Protocol for Electroporation of ES cells. The next protocol in the series is the Protocol on Disaggregation, Expansion, and Freezing of Transfected ES Clones.