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]
The CellTiter-Blue® Cell Viability Assay uses an optimized reagent containing resazurin. The homogeneous procedure involves adding the reagent directly to cells in culture at a recommended ratio of 20µl of reagent to 100µl of culture medium. - [Read Cell Viability Assays that Measure Metabolic Capacity Protocol]
This protocol describes how to use DIG Chem-Link to directly label any DNA [e.g. plasmids, PCR products, cDNA prepared
from mRNA] or RNA (e.g. total RNA, poly(A)+ mMRNA). The
DIG Chem-Link or Biotin Chem-Link may also be used to label oligonucleotides. Includes: Required Purity of DIG Chem-Link Templates; Direct DIG Labeling of mRNA or cDNA with DIG Chem-Link; Key Product Required for Direct Labeling of DNA or RNA; Estimating the Yield of DIG-labeled Nucleic Acids. - [Read Chem-Link Labeling of DNA or RNA with DIG or Biotin Protocol]
Early Events in B Lymphocyte Activation Protocol- https://catalog.invitrogen.com/index.cfm?fuseaction=iProtocol.unitSectionTree&treeNodeID=9E6634190D367003ECF94AE65295FA77&objectid=6674AB8295693316922D8DFC029193A6
B cell activation can be quantitated indirectly by assaying antibody production or directly by measuring cellular changes that occur immediately after exposure to an activation signal. Provides methods for the latter (direct) approach--namely, methods for quantifying early parameters of B cell activation such as increases in intracellular ionized calcium concentration [Ca2+]I, cell size, and MHC class II-antigen expression. - [Read Early Events in B Lymphocyte Activation Protocol]
New screening efforts and chemical modifications of existing compounds have been attempted to identify more selective and potent inhibitors. To determine the selectivity of the inhibitors identified during screening efforts we developed gel-elongation assay using crude bacterial lysate directly to determine the target specificities of fatty acid synthesis inhibitors. - [Read Gel-elongation Assay for Type II Fatty Acid Synthesis Protocol]
This protocol describes a rapid PCR-based method for identifying targeted ES cell colonies prior to picking. It is based on DNA analysis of a small part of colonies pooled directly from selection plates. Only positive colonies are expanded. - [Read Genotyping Embryonic Stem (ES) Cell Colonies Prior to Picking Protocol]
For low-resolution work, cells to be used for staining can be grown directly on regular tissue-culture dishes. It is a convenient method that does not require much preparatory work. - [Read Growing Adherent Cells Directly on Tissue Dishes Protocol]
Protocol describes the direct detection of RNA on DNA microarrays using Hybrid Capture (HC) technology and the HC ExpressArray Kit developed by Diagene. The kit uses a proprietary antibody that binds specifically to RNA:DNA hybrids and a second, fluorescently labeled, antibody that detects the primary antibody. Total RNA is applied directly to a glass-spotted DNA microarray, and stable RNA:DNA hybrids are visualized via a Cy3-labeled secondary antibody. - [Read Hybridization and Detection Using the HC ExpressArray Kit Protocol]
For immunoblotting experiments, it is often important to compare the total amount of an antigen from many different sources or to learn if a particular source has the antigen under study. In the approach described here, tissue cultures, bacteria, yeast cells, tissues, and other sources of antigens are disrupted directly in an electrophoresis sample . - [Read Immunoblotting: Preparing Cell Lysates Protocol]
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]
There are several strategies to visualize the antibody. For transmitted light microscopy, color development substrates for enzymes are often used. The antibody can be directly
labeled with the enzyme. However, such a covalent link between an antibody and an enzyme might result in a loss of both enzyme and antibody activity. For these reasons
several multistep staining procedures have been developed, where intermediate link antibodies are used. In this protocol use the Vectastain ABC-kit. - [Read Immunocytochemistry in Free-Floating Sections 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)]
LCM utilizes an infrared laser integrated into a standard microscope. A transparent cap is attached to a thermoplastic transparent membrane which lies directly on the surface of a routinely prepared tissue section on a glass slide. The investigator examines the tissue section microscopically and activates the laser when the desired cells underlie the target. This in turn activates the membrane with subsequent binding and procurement of the cells of interest. - [Read Laser Capture Microdissection (LCM)]
LCM technology can harvest the cells of interest directly or can isolate specific cells by cutting away unwanted cells to give histologically pure enriched cell populations. A variety of downstream applications exist: DNA genotyping and loss-of-heterozygosity (LOH) analysis, etc. Protocol provides a thorough description of LCM techniques, with an emphasis on tips and troubleshooting advice derived from LCM users. The total time required to carry out this protocol is typically 1–1.5 h. - [Read Laser-capture Microdissection Protocol]
Protocol for preparation of DNA for pulsed-field gel electrophoresis: isolation of DNA from mammalian cells and tissues. Genomic DNAs from mammalian cells are prepared for pulsed-field gel electrophoresis by lysing cells in situ in an agarose plug. Following digestion with an appropriate restriction enzyme, the plug is loaded directly into the well of a pulsed-field gel or it can be melted before loading. - [Read Preparation of DNA for Pulsed-field Gel Electrophoresis: Isolation of DNA from Mammalian Cells]
This protocol focuses on the interactions between L-selectin expressed on neutrophils and PNAd coated onto the plastic surface. The main purpose of the flow chamber assay is to visualize and measure interactions between flowing cells expressing a given adhesion molecule on their surface, and their receptor, either directly coated on the flow chamber lower wall or expressed on a cell monolayer. - [Read Protocol for L-selectin-PNAd Interactions under Flow Conditions.]
GUS is used as a tag to address nuclear localization whereas GFP is more versatile. GFP is detectable directly in living cells, GUS is only detected indirectly by staining of fixed tissue which may lead to artifacts or may obscure problems with protein solubility. In this protocol, protein localization is routinely assayed after particle-mediated transient transformation of onion epidermal cells. With this method it can be determined rapidly whether a given fusion protein is active and.... - [Read Subcellular Localization of GUS- and GFP-Tagged Proteins in Onion Epidermal Cells]
Technique yields a heterogeneous population of short radiolabeled molecules 200-300 nucleotides in length. These probes are synthesized, as in Synthesis of Single-stranded DNA Probes of Defined Length from Bacteriophage M13 Templates, by extension of an oligonucleotide primer on a single-stranded DNA template. The radiolabeled products of the reaction are then separated from the template by electrophoresis through a denaturing gel from which they are eluted directly into hybridization buffer. - [Read Synthesis of Single-stranded DNA Probes of Heterogeneous Length from Bacteriophage M13 Templates]
Protocol describes the use of FLAG-epitope-tagged proteins for both small-scale analysis and large-scale coimmunoprecipitation of interacting proteins. When examining protein interactions, it is sometimes possible to immunoprecipitate an endogenous protein X directly, without using an epitope tag, if antibodies are available. The advantage of examining interactions of endogenously expressed proteins is that these are likely to be physiological and less likely to be an artifact of overexpression. - [Read Using FLAG Epitope-Tagged Proteins for Coimmunoprecipitation of Interacting Proteins Protocol]
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.