The method allows the detection and quantification of glycosyltransferase activity using an ELISA-based procedure and carbohydrate-specific monoclonal antibodies. Avoids the use of radiolabeled substrates. Bruce A. Macher~Professor of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA - [Read A Sensitive ELISA-Based Assay for Glycosyltransferases]
Enzyme-linked reagents give excellent sensitivity and use a simple light microscope for detection. A range of enzymes is available, but for staining in situ, horseradish peroxidase will suit most needs. Diaminobenzidine (DAB) is one of the most sensitive substrates for horseradish peroxidase. It yields an intense brown product that is insoluble in both water and alcohol. It can be made more sensitive by adding metal salts such as cobalt or nickel to the substrate solution. - [Read Antibody Addition to Drosophila Specimens and Detection Using Enzyme-Linked Reagents 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]
In vitro transcription reactions employing T3, T7 or SP6 phage-encoded RNA polymerases are widely used to synthesize RNA from recombinant vectors containing appropriate promoters. Production of large amounts of specific RNA is valuable in the preparation of hybridization probes and in vitro translation studies; in the synthesis of ribozymes, rRNA, SRP, antisense RNA and substrates for RNA splicing; and in RNA-protein interaction studies. - [Read Protocol: Purification of In Vitro Synthesized mRNA with Microcon or Centricon Centrifugal Filters]
Protocol for the purification of DNA recovered from agarose and polyacrylamide gels by anion-exchange chromatography. Fragments of DNA recovered from agarose gels are sometimes poor templates or substrates in subsequent enzymatic reactions. This problem can be solved by binding the DNA to a positively charged matrix, such as DEAE-Sephadex or DEAE-Sephacel, in buffers of low ionic strength. After washing the matrix, the DNA is eluted by raising the strength of the buffer. - [Read Purification of DNA Recovered Anion-exchange Chromatography Protocol]
Use of the chemiluminescence-producing alkaline phosphatase substrate 3-(4-methoxyspiro[1,2-dioxetane-3,2'-tricyclo-[3.3.1.1(3,7)]decan]-4-yl)phenyl phosphate (AMPPD, also known as adamantyl-1,2-dioxetane phosphate), or its dioxetane relatives provides a substantial increase in sensitivity over colorimetric substrates and radiochemical methods currently used for the detection of antigen-antibody complexes immobilized on nylon or PVDF membranes. - [Read Western Analysis Using the Chemiluminescent Alkaline Phosphatase Substrate CSPD Protocol]