There are two basic methods for the in vitro assay of B-galactosidase activity from yeast. They
differ mainly in the method of preparing the material for assay. Both methods are described with accompanying protocols. Method I: Assay of Crude Extracts includes: Yeast Cell Growth; Yeast Cell Harvest; B-gal assays; Bradford Assays. Method II: Permeabilized cell assay. - [Read Assay of β-Galactosidase in Yeast Protocol]
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]
With this protocol, transcripts that were initiated from specific genes by RNA polymerases prior to permeabilization can be measured. Instead of a nuclear extract, permeabilized cells are used. Includes information on: Permeabilization of Cells; In vitro Transcription Reaction (Run-off); Isolation of RNA; Preparation of Slot Blot Membrane for Hybridization; Hybridization of Nitrocellulose Membrane; TCA Precipitation to Determine Incorporation of [32P] GTP into Nucleic Acid - [Read In Vitro Transcription Assay (Run-off Assay) using Permeabilized Cells]