Phalloidin binds specifically to F-actin, and fluorescent-tagged phalloidin stains the actin skeleton in cells in a manner that is very close to the staining pattern seen using anti-actin antibody. - [Read Actin Staining in Fixed Yeast Cells Protocol]
Simple and universally applicable methods for staining fixed cells are presented, as are methods that utilize detergents and proteolytic treatment to permeabilize cells. Additionally, supravital cell staining with Hoechst 33342, which is primarily used for sorting live cells for subsequent culturing based on DNA-content differences, is also described. Also presented are methods for staining of cell nuclei isolated from paraffin-embedded tissues, and deconvolution of DNA-content-frequency... - [Read Analysis of Cellular DNA Content by Flow Cytometry Protocol]
A sensitive method for the detection of apoptosis by single laser flow cytometry. Methodology includes: Staining for detection of apoptosis, Direct Staining Procedure, Indirect Staining Procedure, Protocol for the use of actinomycin D (AD) on samples that were stained with 7-AAD for apoptosis and fixed in formaldehyde. - [Read Apoptosis Detection Protocol By Single Laser Flow Cytometry]
Once tissues are fixed and permeabilized, the antibodies are added. These antibodies can be labeled directly or detected by a labeled secondary reagent. For indirect detection, any reagent that binds specifically to the primary antibody can be "tagged" and used to locate the antibody. The possible reagents include anti-immunoglobulin antibodies, protein A or G, or, if the first antibody is labeled with biotin, streptavidin. They can be labeled with enzymes or gold. - [Read Binding Antibodies to Tissue Sections Protocol]
Flow cytometers must be calibrated prior to fluorescence intensity measurements because of inherent instrument variability. To correct for this variability, a standard particle (fixed chicken red blood cells, or CRBCs) must be analyzed on the instrument prior to each experiment and photomultiplier tube (PMT) voltages adjusted accordingly to place the CRBC fluorescence emission peaks into predetermined target channels. - [Read Calibration of Becton Dickinson Flow Cytometers for Relative Fluorescence Intensity Measurements]
Protocol describes the use of a basic water-based dye to stain for acid mucosubstances and acetic mucins located on the cartilage of fixed embryos, permitting the examination of cartilage formation. - [Read Cartilage Staining of Xenopus tropicalis Protocol]
Protocol describes the use of chromatin immunoprecipitation technology (ChIP) to analyze interactions of proteins or protein complexes with DNA in vivo. In this approach, the material is fixed with formaldehyde to preserve DNA-protein and protein-protein associations, the cells are lysed, and the chromatin is cut and solubilized. The chromatin suspension is immunoprecipitated with an antibody against the protein(s) of interest, and the coimmunoprecipitated DNA fragments are analyzed. - [Read Chromatin Immunoprecipitation (ChIP) of Protein Complexes Protocol]
Investigators can utilize X chromosome inactivation (methylation) to determine the clonality status of a tumor or premalignant lesion in females. The technique is based on a methylation-sensitive restriction enzyme and analysis of a polymorphic locus on the X chromosome. Clonal cell populations will show "loss" of the non-methylated allele after restriction digest. The assay can be performed on DNA recovered from microdissected samples. Both frozen tissue and fixed-embedded tissue can be used. - [Read Clonality - X Chromosome Inactivation Assay Protocol]
Protocol for double immunofluorescence staining for BCL-6. Any type of tissue is suitable for this technique, as long as the antigenicity for your antigen(s) is preserved. Includes: unfixed or acetone-fixed specimens; dewaxed, antigen retrieved slides. - [Read Double Immunofluorescence Staining for BCL-6 Protocol]
Treating cells with paraformaldehyde leads to the establishment of chemical cross-links between free amino groups. When the cross-links join different molecules, a latticework of interactions occurs that holds the overall architecture of the cell together. Commercial formaldehyde solutions are not recommended, because they lack the advantages of using a variable-length polymer, and the cells will simultaneously be fixed with the alcohol (usually methanol). - [Read Fixing Attached Cells in Paraformaldehyde Protocol]
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]
In recent years, the increased sensitivity of electron detectors and the availability of low-vacuum or variable-pressure systems have allowed imaging of fresh tissue samples without the need for fixation, drying, and coating. This obviously saves a lot of time, although the image quality may not be as good as that obtained from fixed samples. However, for most applications that tend to be at a relatively low magnification, the quality can be as good as that obtained from fixed samples. - [Read Imaging of Fresh Arabidopsis Tissues in the Scanning Electron Microscope]
In recent years, the increased sensitivity of electron detectors and the availability of low-vacuum or variable-pressure systems have allowed imaging of fresh tissue samples without the need for fixation, drying, and coating. This obviously saves a lot of time, although the image quality may not be as good as that obtained from fixed samples. However, for most applications that tend to be at a relatively low magnification, the quality can be as good as that obtained from fixed samples. - [Read Imaging of Fresh Arabidopsis Tissues in the Scanning Electron Microscope Protocol]
Protocol for immunohistochemistry on fixed, paraffin-embedded sections. This method is widely used and applies to the detection of the overwhelming majority of antigens, with few exceptions for which enzymatic retrieval is required. The method uses a strong chelating agent, EDTA. Includes: Double indirect AP; AP Developing solution; Indirect immunohistochemistry with avidin-biotin and HRP; HRP Developing solution. - [Read Immunohistochemistry on Fixed, Paraffin-Embedded Sections Protocol]
Protocol describes the application of peroxidase or alkaline phosphatase conjugates in the immunohistochemical labeling of formalin-fixed, paraffin-embedded tissue sections. Includes: Removal of Paraffin and Rehydration; Antigen Retrieval - Unmasking of Antigen; Enzyme retrieval; Microwave retrieval; Inactivation of Endogenous Peroxidase; etc.. - [Read Immunohistochemistry Protocol]
This protocol describes a method for quantitative measurement of DNA using propidium iodide (PI) staining and flow cytometry. PI stains all double-stranded regions of both DNA and RNA by intercalating between the stacked bases of the double helix. PI cannot penetrate an intact cell membrane; therefore, cells are fixed prior to staining. The ethanol-fixed cells can be stored unstained at 4°C for days, or even weeks, and then stained and analyzed. - [Read Measurement of DNA Content Using Propidium Iodide (PI) Staining of Fixed Whole Cells Protocol]