The Gemini™ XPS and EM Microplate Readers with dual monochromators provide a flexible environment to determine the optimal excitation and emission settings for fluorescence intensity assays. Multiple-point well scanning optimizes cell-based assay sensitivity. Comparison of relative fluorescence units (RFUs) between samples is allowed by a unique calibration against an internal standard. Temperature-sensitive reactions are monitored with consistent temperature regulation from ambient to 45°C.
Monitoring levels of cAMP, a second messenger produced in response to activation of adenylate cyclase, is one of the most common ways to screen for agonists and antagonists of Gi/Gs protein-coupled receptors. cAMP levels can be monitored using fluorescent molecules that bind to cAMP and are detected using a fluorescence plate reader.
Here are a few application notes on cAMP assays (GPCR) you may find of interest:
Apoptosis is a highly regulated cellular program that causes cell death in normal processes such as embryonic development, as well as diseases including cancer and neurodegenerative conditions. Assays for apoptosis can be performed using a variety of imaging or microplate reader detection systems and provide valuable information on normal and disease-related mechanisms of cell death.
Learn about a Caspase-3 single-step, homogenous assay that is specifically designed for microplate readers:
Cell viability refers to the number of healthy cells in a population and can be evaluated using assays that measure enzyme activity, cell membrane integrity, ATP production, and other indicators. These methods can employ luminescent, fluorescent, or colorimetric readouts as indicators of general cell viability or even specific cellular pathways. Cytotoxicity and cell viability assays are often used to assess a drug or other treatment’s effect, and are valuable tools in the search for new therapeutics, as well as advancing our understanding of how normal cells function.
Quantitation of cell proliferation using fluorescence allows one to easily monitor the effects of drugs and other experimental treatments on cell growth.
This application note describes two assay methods of a cell prolfieration. In the first, cellular proliferation is quantitated using a cell-based standard curve. In the second, cellular proliferation is quantitated using RNase-treated cell samples and a DNA standard curve.
Development of predictive in vitro assays suitable for safety and efficacy testing is of high interest for improving the drug development process and reducing drug attrition. There has been great interest in using stem cells as tools for screening compounds during early drug development.
In this scientific poster, we present results obtained from one of our multi-mode plate readers for performing toxicity assessment of various compounds using stem cell-derived cell models in a high throughput manner:
The drug discovery landscape is shifting, with more scientists centering cell line development, disease models, and high-throughput screening methods around physiologically-relevant 3D cell models. The reason for this is clear: Using cellular model systems in research that closely mimic patient disease states or human organs can bring life-saving therapeutics to market – faster.
Cell viability assays are critical to a broad spectrum of research areas ranging from investigation into the mechanisms of cell death to the development of new therapeutics targeting apoptosis in diseases. One of the most popular detection technologies for cell viability is a fluorescence microplate reader.
Here are a few applications you may find of interest:
Enzyme-linked immunosorbent assays (ELISAs) are used to measure the amount of a specific protein, using a microplate format, and results are most often detected via absorbance in the visible wavelength range. Chemiluminescent and fluorescent ELISA formats offer enhanced sensitivity for accurate quantitation of less abundant analytes.
Learn all about fluorescence detection – what it is, how it works, and the instruments used to measure the fluorescence of a sample. We also cover many fluorescence-based assays including cell viability, GPCR activity, and fluorescent nucleic acid quantification.
Fluorescent proteins have become enormously popular as tools for monitoring biological events in vivo. In addition to green fluorescent protein (GFP) from the jellyfish Aequorea victoria, there are now numerous others available from other species of jellyfish and reef coral. These proteins can be expressed in a diverse range of cells and organisms, where they are used to track many cellular processes, including protein synthesis and translocation, gene induction, and cell lineage.
Proteins inside eukaryotic cells exist in a dynamic state, in a highly-regulated balance between synthesis and degradation. Whereas protein synthesis is well-understood after decades of study, major advances in our knowledge of protein degradation have occurred only in the last two decades.
Learn more about fluorescent protein in our application note:
Microbes, including bacteria, have been estimated to make up about 15 percent of the earth’s biomass, and microbes in the human body outnumber human cells by 10 to 1. These microorganisms provide great benefit to us and are also vital to many fields of research from medicine to alternative energy production. On the other hand, monitoring for microbes and the toxic substances they produce is necessary to ensure the safety of pharmaceutical products. Scientists whose research relies on mammalian cells must carefully monitor these cultures for unwanted microbial contaminants to ensure that their experimental results are reliable.
Nucleic acids are large biomolecules common to all known life forms. Deoxyribonucleic acid (DNA) consists of a double strand of pairs of nucleotides, while ribonucleic acid (RNA) is typically a single strand. In DNA, the nucleotides are adenine, cytosine, guanine, and thymine, while RNA contains uracil instead of thymine. DNA makes up the genetic material of all organisms, encoding the information cells need to synthesize proteins.
Protein detection, quantitation, and analysis are central to the investigation of a wide variety of biological processes. Measuring the concentration of protein is necessary to processes ranging from protein purification and labeling to sample preparation for electrophoresis. Protein can be quantitated directly via absorbance at 280 nm, or indirectly using colorimetric (BCA, Bradford, etc.) or fluorometric methods offering advantages such as greater sensitivity. To identify and measure a specific protein within a complex sample, for example, serum or cell lysate, an ELISA may be used.
The intrinsic fluorescence of proteins is due to the aromatic amino acids tryptophan, tyrosine, and phenylalanine. Tryptophan dominates the emission of proteins and is the most sensitive to solvent polarity and the local environment. Analysis of changes in tryptophan fluorescence can yield information on protein denaturation and conformation.
In these application notes, we demonstrate performance of the SpectraMax® multi-mode microplate readers for assays measuring intrinsic tryptophan fluorescence.
Publications
According to Biocompare, “one of the most overlooked pieces of equipment in any lab is the microplate reader. While they play an important role in generating data from a wide range o…
Application Note
Accurate quantification of nucleic acid concentration is important for downstream applications including transfection, cloning, PCR, and next generation sequencing (NGS). Often, these…
Publications
The pharmaceutical world is a highly regulated environment. And for good reason. As a potential drug moves through the development process – from the in vitro discovery phase, to pre…
Blog
The regulations for food and drug in the United States, described in the Title 21 of the Code of Federal Regulations, and the EudraLex Annex 11 in EU, are critical in ensuring safe…
Blog
For over 40 years, Molecular Devices has been at the forefront of technological advances which have contributed to significant scientific breakthroughs. To kick off the new year, we…
Application Note
Double-stranded DNA is typically quantitated in microplate readers by measuring the absorbance of the DNA solution at 260 nm. However, this method is only able to measure down to about…
Customer Breakthrough
Resistance to insecticides is a major obstacle to controlling insect pests in a sustainable manner in the agricultural industry. Aware of this issue, Dr Graham Moores founded ApresLa…
Application Note
This application note describes how to use the NanoOrange® Protein Quantitation Kit from Life Technologies in SpectraMax® microplate readers with the fluorescence detection mode and…
eBook
Accurate and sensitive detection of nucleic acids and proteins are critical to many experiments.
Application Note
Quantitation of cell proliferation using fluorescence allows one to easily monitor the effects of drugs and other experimental treatments on cell growth. The CyQUANT Cell Proliferation…
Scientific Poster
Cyclic AMP is involved in intra- and inter-cellular signaling in organisms as diverse as bacteria, slime mold, fruit flies and humans (4, 5, 8, 9). Cyclic AMP is produced from ATP by…
Data Sheet
The SpectraMax® Gemini™ XPS Microplate Spectrofluorometer from Molecular Devices® provides a flexible environment to determine the optimal excitation and emission settings for most f…
Scientific Poster
The proteasome is a massive protein complex inside all eukaryotic cells (and some bacteria) that removes unnecessary proteins by breaking them down into short peptides. It consists o…
Data Sheet
Explore how the Gemini EM Microplate Reader is a flexible spectrofluorometer capable of running many fluorescence-based assays using its dual monochromator system.
Brochure
Molecular Devices is a leading provider of high-performance bioanalytical measurement solutions for life science research, pharmaceutical development, and biotherapeutic discovery. O…
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Gene based therapy represents an important advance in the treatment of diseases that heretofore have had either no treatment or cure. To capitalize on the true potential of gene therapy, there is a need to develop better delivery systems that can protect these therapeutic biomolecules and deliver them safely to the target sites. Recently, we have designed and developed a series of novel amino acid-substituted gemini surfactants with the general chemical formula C12H25(CH3)2N+- (CH2)3-N(AA)-(CH2)3-N+(CH3)2-C12H25 (AA= glycine, lysine, glycyl-lysine and, lysyl-lysine). These compounds were synthesized and tested in rabbit epithelial cells using a model plasmid and a helper lipid. Plasmid/gemini/lipid (P/G/L) nanoparticles formulated using these novel compounds achieved higher gene expression than the nanoparticles containing the parent unsubstituted compound. In this study, we evaluated the cytotoxicity of P/G/L nanoparticles and explored the relationship between transfection efficiency/toxicity and their physicochemical characteristics (such as size, binding properties, etc.). An overall low toxicity is observed for all complexes with no significant difference among substituted and unsubstituted compounds. An interesting result revealed by the dye exclusion assay suggests a more balanced protection of the DNA by the glycine and glycyl-lysine substituted compounds. Thus, the higher transfection efficiency is attributed to the greater biocompatibility and flexibility of the amino acid/peptide-substituted gemini surfactants and demonstrates the feasibility of using amino acid-substituted gemini surfactants as gene carriers for the treatment of diseases affecting epithelial tissue.
The chemokine receptor CXCR5 is predominantly expressed on mature B cells and follicular T-helper cells. CXCR5 and its ligand CXCL13 participate in ectopic germinal center formation at the inflammatory sites of multiple immune diseases such as rheumatoid arthritis, multiple sclerosis, and Sjogren’s syndrome. Therefore, disrupting CXCL13-induced chemotaxis may be a fruitful approach for developing therapeutics in treating these diseases. Cells undergo cytoskeletal rearrangement prior to chemotaxis, and therefore actin polymerization can be used as a surrogate readout more proximal to chemokine receptor activation than chemotaxis. Conventionally, actin polymerization is measured by fluorescence microscopy or flow cytometry, which are either of low throughput or in need of special instruments. We developed a 96-well actin polymerization assay that can process 1,000 to 1,500 samples a day. This assay uses a standard laboratory fluorescence microplate reader as the detection instrument and was optimized for various experimental conditions such as cell density, actin filament staining reagent, staining buffer, and cell culture conditions. We demonstrate that this actin polymerization assay in 96-well format exhibits the expected pharmacology for human CXCR5 and is suitable as a primary functional assay to screen neutralizing scFv in crude bacterial peri-preps and a secondary assay for small compound collections.
A number of macromolecular probes employing different carriers and a number of microparticular probes employing different oxygen sensitive dyes were fabricated, giving a panel of oxygen sensitive probes. The photophysical and oxygen sensing properties of these probes were examined comparatively. The probes were used successfully to monitor cellular oxygen uptake and their ability to overcome a number of problems associated with oxygen sensing in biological samples was assessed. Macromolecular probes proved sufficient in a number of cases, particularly where spectral solutions can resolve the interferences. However where physical interactions cause interference the added protection of the polymer in the particle based probes was required.
Product | Product Number |
Gemini XPS Microplate Reader | XPS |
SpectraTest FL1 Fluorescence Validation Plate | 0200-5060 |
SpectraDrop™ Micro-Volume Microplate Starter Kit | 0200-6262 |
SpectraDrop™ Micro-Volume HTS Kit | 0200-6267 |
StakMax Microplate Handling Stacker | StakMax |
Microplate Reader Shelf | 9000-0756 |
Product | Part Number |
Gemini EM Microplate Reader | EM |
SpectraTest FL1 Fluorescence Validation Plate | 0200-5060 |
SpectraDrop™ Micro-Volume Microplate Starter Kit | 0200-6262 |
SpectraDrop™ Micro-Volume Microplate HTS Kit | 0200-6267 |
Microplate Reader Shelf | 9000-0756 |