The pH is an important parameter controlling many metabolic and signalling pathways in living cells. Recombinant fluorescent pH indicators (pHluorins) have come into vogue for monitoring cellular pH. They are derived from the most popular Aequorea victoria GFP (Av-GFP). Here, we present a novel fluorescent pH reporter protein from the orange seapen Ptilosarcus gurneyi (Pt-GFP) and compare its properties with pHluorins for expression and use in plants. - [Read A Novel Fluorescent pH Probe for Expression in Plants]
The assay for ß-galactosidase relies on the ability of the enzyme to catalyze the hydrolysis of ONPG (o-nitrophenyl-ß-D- galactopyranoside) to free o-nitrophenol, which absorbs light at 420 nm. In this protocol, extracts of cells transfected with a ß-galactosidase reporter plasmid are incubated with ONPG. - [Read Assay for ß-galactosidase in Extracts of Mammalian Cells]
In this protocol, cells transfected with a luciferase reporter plasmid are lysed in a detergent-containing buffer. Luciferase in the extract catalyzes an oxidation reaction in which D-luciferin is converted to oxyluciferin, with production of light at 556 nm that can be quantified in a luminometer. - [Read Assay for Luciferase in Extracts of Mammalian Cells Protocol]
It is possible that some cell lines have lost the ability to perform RNAi or that cells derived from certain tissues do not support RNAi. This reporter assay, for RNAi in mammalian cells, can be used to establish whether the cells under study are susceptible to RNAi. - [Read Cotransfection of Luciferase Reporter Plasmids with siRNA Duplexes Protocol]
Protocol should be viewed as a starting point for systematic optimization of transfection mediated by lipofecting agents. Once a positive signal has been obtained from a transfected plasmid carrying a standard reporter gene, optimal conditions for transfection can be established by systematic variation of parameters such as the initial cell density, the amount and purity of DNA, the media and serum, and the time of exposure of the cells to the cationic-lipid-DNA complex. - [Read DNA Transfection Mediated by Lipofection Protocol]
Protocol for GUS reporter gene assay. Includes: Protein isolation; Alternative method for small (<1g) quantities of tissue; GUS assays; Bradford protein concentration determination assays - [Read GUS Reporter Gene Assay 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)]
In this protocol, extracts prepared from cells transfected with a chloramphenicol acetyltransferase (CAT) reporter plasmid are incubated with radiolabeled chloramphenicol. The acetylated products generated by the action of CAT are separated from the unmodified drug by thin-layer chromatography and quantitated by scraping the spots from the thin-layer plates and counting them by scintillation spectroscopy. - [Read Measurement of CAT in Extracts of Mammalian Cells Using Thin-layer Chromatography]
The latest generation of Promega cell-based assays includes luminescent and fluorescent chemistries to measure markers of cell viability, cytotoxicity and apoptosis, as well as to perform reporter analysis. Using these tools researchers can investigate how cells respond to growth factors, cytokines, hormones, mitogens, radiation, effectors, compound libraries and other signaling molecules. The protocols provided are guidelines for multiplexing cell-based assays & are intended as starting points. - [Read Multiplexing Cell Viability Assays Protocols]
This protocol describes a method for reverse transcriptase (RT) in situ PCR. In situ PCR differs from PCR in situ hybridization in the inclusion of a reporter molecule in the amplification step. The two steps of RT in situ PCR that differ from in situ PCR are overnight digestion in RNase-free DNase that is performed after protease digestion, and an RT step, prior to in situ PCR. - [Read Reverse Transcriptase In Situ PCR Protocol]
Protocol describes a method for reverse transcriptase (RT) in situ PCR. In situ PCR differs from PCR in situ hybridization in the inclusion of a reporter molecule in the amplification step. The two steps of RT in situ PCR that differ from in situ PCR are overnight digestion in Rnase-free Dnase that is performed after protease digestion, and an RT step, prior to in situ PCR. - [Read Reverse Transcriptase In Situ PCR Protocol]
Protocol describes a split luciferase complementation assay used to study the interaction of proteins in cells. In the split protein strategy, a single reporter protein/enzyme (firefly luciferase [Fluc]) is cleaved into amino-terminal and carboxy-terminal halves; each half is fused to one of two interacting proteins, X & Y. Physical interactions between the two proteins reconstitute the functional reporter protein, leading to enzymatic activities that can be measured by in vitro or in vivo assay - [Read Split Luciferase Complementation Assay for Studying Interaction of Proteins X and Y in Cells]
Protocol describes a split luciferase complementation assay that can be used to repetitively and noninvasively study the interaction of proteins in small living animals. After the expression of the appropriate vectors has been checked in cell culture in vivo, studies can be performed either by implanting transiently transfected cells for short-term analysis (maximum of 7 days), or with tumor models grown from tumor cells stably expressing the complete reporter system. - [Read Split Luciferase Complementation Assay for Studying Interaction of Proteins X and Y in Living Mice]
Transfection of primary leukocytes has traditionally been a challenging but much desired protocol. It allows not only the analysis of cells in a more natural state to a cell line system, it enables the direct comparison of, for e.g. transcriptional activity using luciferase reporters, in immune cells taken from genetically-altered mice. In addition, importantly it allows for "rescue experiments" in knockout cells & the ability to over-express or reconstitute wild-type and/or mutated constructs. - [Read Transfection of Bone Marrow-Derived Mast Cells for Transcription Factor Luciferase Reporter Assays]
Protocol describes a method for the delivery of siRNAs into mammalian cells in the absence of reporter plasmids. This is best achieved with transfection reagents developed for the delivery of antisense oligodeoxynucleotides. The quantities of reagents given below are calculated for the transfection of one well of a 24-well plate. - [Read Transfection of Mammalian Cells with siRNA Duplexes Protocol]
Protocol describes a method for the delivery of siRNAs into mammalian cells in the absence of reporter plasmids. This is best achieved with transfection reagents developed for the delivery of antisense oligodeoxynucleotides. The quantities of reagents given below are calculated for the transfection of one well of a 24-well plate. - [Read Transfection of Mammalian Cells with siRNA Duplexes Protocol]
This procedure, which uses a root transformation protocol, provides a rapid method for assessing gene expression in Arabidopsis roots. It is useful for testing promoter:reporter gene constructs, for expressing genes, the overexpression of which is lethal in whole plants, and for transforming the roots of plants that are recalcitrant to conventional transformation techniques. The protocol has been used successfully with Ws, No-0, and RLD ecotypes. - [Read Transgene Expression in Regenerated Roots]