Comprehensive Antibody Characterisation

11 Mar 2008

Product news

Guava Technologies, Inc., a leading developer of easy-to-use, on-demand, benchtop cell analysis systems, provides new levels of flexibility and analysis with its Guava RapidQuant™ IgG Assays for quantification of mouse and human antibodies.

Used in combination with the Guava Express®, Guava ViaCount® and other Guava® Assays the new Guava RapidQuant IgG Assays provide unmatched antibody characterisation on a single cellular analysis platform - the Guava EasyCyte™ Plus ™ System.

With their simplicity and ease of use, the new microplate-based Guava RapidQuant™ IgG Assays have raised the bar for IgG titering in tissue culture supernatants. Designed to be time-saving, labour-saving and money-saving, RapidQuant Assays eliminate the most tedious portions of antibody titering methods. The no wash RapidQuant Assays are bead-based and rely on sensitive fluorescence detection for the quantitative measurements. Standard curves are automatically produced by the easy to use software interface, removing the need for time consuming calculations performed by the user during analysis. The fluorescent intensity is proportional to the concentrations of antibody captured on the beads. Using fluorescence provides tremendous reliability and precision so you can have confidence in every result. RapidQuant Assays have been tested extensively with human and mouse antibodies of all IgG subtypes and in many types of hybridoma media and have performed well in all cases tested. RapidQuant Kits are extremely specific for IgG and are not hindered by the presence of FBS or IgM in the media. The RapidQuant Assay can be used to determine absolute concentrations of antibody present in cell culture medium or in purified preparations by comparison to a standard curve. Results from this assay can also be combined with results from the Guava Express Assay to determine relative antibody affinities.

The Guava ViaCount® Assay has become a leading standard for viability and cell counting. Used in laboratories characterising antibodies the ViaCount Assay provides a rapid and reliable assessment of the cell concentration and viability of clones for production. Combining results from the RapidQuant and ViaCount Assays delivers the benefit of simultaneous assessment of IgG production and cell health parameters.

The complete antibody characterisation suite from Guava Technologies extends your capabilities for assessing target activity of antibody clones, or identifying cell populations that express a specific protein marker. For example, the Guava Express® Assays provide superior sensitivity and excellent discrimination between cells expressing low and high levels of antigen recognised by the antibody and may also be used to obtain information on specificity of antibodies in the screening steps. The Guava Nexin® and Guava® Cell Toxicity Assays deliver reliable results concerning the potency of the antibody to mediate apoptotic induction and cell killing, respectively. Using the RapidQuant, Express and other Guava Assays provides a highly specific and quantitative assessment tool for obtaining multiple layers of information about your antibodies.

Optimised for use with Guava® microcapillary flow cytometry systems, all Guava Assays, including RapidQuant, Guava Express and ViaCount, require very small volumes of sample for accurate antibody characterisations enabling multiple analyses of each supernatant to be performed from a single 96-well plate.

Faster and easier than the average enzyme-linked immunosorbent assay (ELISA), the traditional approach for antibody quantification, the Guava RapidQuant IgG Assays efficiently quantify the amount of antibody present. When coupled with the suite of other available microplate-based Guava Assays more comprehensive data on antibodies can be generated enabling users to conveniently and productively select optimal clones from hybridoma screens.

RapidQuant™ Mouse & Human IgG Antibody Quantification Assays

Merck

Quick and Easy Antibody Quantitation:With its simplicity and ease of use, Guava’s new RapidQuantTM IgG Kits have raised the bar for IgG titering assays. Designed to be time-saving, labor-saving and money-saving, Guava’s RapidQuant kits eliminate the most tedious, laborious portions of antibody titering methods with Guava’s signature ease of use. • Robust, rapid and highly reproducible • Relevant quantitative range • Quantifies most IgG subtypes equivalently • Nearly twice as fast as typical ELISA assays • Ideal for use with robotic plate handler automation Guava RapidQuant kits are bead-based assays that rely on fluorescence for the quantitative measurements. The fluorescent intensity is proportional to the concentrations of antibody captured on the beads. The assay can be used to determine relative Ab production levels by different hybridoma clones or to determine absolute concentrations of antibody by comparison to a standard curve. Using fluorescence provides tremendous reliability and precision so you can have confidence in every result. RapidQuant assays have been tested extensively with both human and mouse antibodies of all IgG subtypes and in many types of hybridoma media and have performed well in all cases tested. RapidQuant IgG kits are extremely specific and will not be hindered by the presence of FBS or IgM in the media. RapidQuant kits also require very small volumes of sample for accurate determinations of antibody concentation so you can perform multiple analyses of each supernatant from a single 96-well plate. Unlike many current colorimetric immunoassays, the fluorescence readout allows multiple plates to be prepared, refrigerated and read hours or days later, without a loss of signal. This unprecedented stability and robustness makes the assay ideal for large scale screening on robotic systems where multiple plates are prepared prior to sampling.

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ViaCount™ Assay

Merck

Guava Technologies' ViaCount assay is revolutionizing the way cell counting and viability assessment are done in today's laboratories. Fast, automated, and highly reproducible, the Guava ViaCount assay addresses many of the difficulties of conventional cell counting and viability assessment methods. The Guava ViaCount assay provides: Cell counts up to ten times faster than manual counting, in a convenient turnkey assay. Accurate, reproducible counts with very low density cell samples or small sample volumes. Absolute cell counts, viability assessments and apoptotic cell counts in a single measurement. By providing data on all these cell populations in a single measurement, the Guava ViaCount assay enables a more precise evaluation of culture conditions and viable cell populations so you can best optimize culture conditions. Flexibility for many cell types. Accurately counts adherent, clumpy and even non-mammalian cells, such as insect cell lines. More experimental consistency. These precise, accurate cell counts can provide more consistency in experiments that require accurate viable cell counts for success, such as ELISpot, cell-based fluorescence assays or cytokine production assays. The Guava ViaCount assay uses proprietary easy-to-use Guava software, and reagent kits optimized for use with the Guava PCA and PCA-96 systems. Guava ViaCount is fast becoming the method of choice for monitoring cell culture or bioreactor conditions and cell count/viability assessments.

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Nexin Assay Kit

Merck

The new Guava Nexin® reagent monitors induction of apoptosis quickly and easily, with minimal chance for contamination. Annexin V is a calcium-dependent phospholipid binding protein with high affinity for phosphatidylserine (PS), a membrane component normally localized to the internal face of the cell membrane. Early in the apoptotic pathway, molecules of PS are translocated to the outer surface of the cell membrane where Annexin V can readily bind them. The Guava Nexin® assay incorporates this PS-Annexin V binding as an indicator of early stage apoptotic cells. The Guava Nexin® assay kit utilizes Annexin V-PE to detect PS on the external membrane of apoptotic cells. The cell impermeant dye 7-AAD is included in the Nexin kit as an indicator of membrane structural integrity. 7-AAD is excluded from live, healthy cells and early apoptotic cells, but permeates late stage apoptotic and dead cells. The following populations of cells can be distinguished in this assay: Non-apoptotic cells: Annexin V(-) and 7-AAD(-) Early apoptotic cells: Annexin V (+) and 7-AAD(-) Late stage apoptotic and dead cells: Annexin V(+) and 7-AAD(+)

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AntibodiesAntibodies are used in techniques such as confocal and fluorescence microscopy, flow cytometry, ELISA, ELISPOT, immunohistochemistry, western blotting and immunopreciptation. Select specific antigen reactivity, high specific affinity, low non-specific binding, monoclonal or polyclonal, primary or secondary antibodies and associated conjugates such as an enzyme or dye for visualization.ELISAEnzyme-linked immunosorbent assays (ELISA), also known as enzyme immunoassays (EIA), are used for the detection and quantification of proteins, peptides and antibodies in a sample. ELISA often comes in kit format, with pre-selected antibody pairs to detect specific proteins or biomarkers of diseases such as diabetes and obesity, or cardiovascular and neurological disorders. Detection is made possible with chemiluminescent, fluorescent or colorimetric substrates and detection instruments such as microplate / ELISA readers. Other kits available include: Enzyme-linked immunospot (ELISPOT) assays for the quantification of protein-producing cells and chemiluminescent immunoassays (CLIA) kits. Find the best ELISA kits and products in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.MicroplatesMicroplates are multi-well plates used to increase the throughput of biological investigations. The number of wells microplates contain can range from 6 to 3243 wells, with the 96-well format being the most commonly used. Microplates can come tailored for a range of applications including cell culture, PCR, filtration, storage, non-binding surface, protein crystallization, as well as pre-coated, deep well and normal Standard microplates. Additionally, options for microplate colors include clear , black, white or black with clear bottom and white with clear bottom for absorbance microplate reader applications. Find the best microplates for your lab in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.ADME-ToxicologyADME-toxicology (ADME-Tox) studies are used in pharmacology and pharmacokinetics to assess the activity/toxicity of drugs <i>in vivo</i> or <i>in vitro</i>. Find bioassays for absorption, distribution, metabolism, and excretion of drug molecules including cytotoxicity, transporter/permeability, metabolism and activity assays as well as hepatocytes and cell lines for ADME. Find the best ADME-toxicology products in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Flow Cytometry / Cell CountingFlow cytometers are used to count, sort and examine multiple characteristics of cells. Other cell analysis equipment includes image cytometers, cell counters, fluorescence-activated cell sorters (FACS), magnetic-activated cell sorters (MACS), and a range of flow cytometry assay kits. Flow cytometers can reveal information on cell viability, cell proliferation, apoptosis and cell cycle progression, as well as identify cell populations and intracellular or cell-surface molecules. Additionally, some flow cytometers, known as FACS, have an additional sorting function after analysis. Cell counters and image cytometers count live and dead cell populations and can also conduct cell proliferation assays. Find the best flow cytometers, cell counters and cell sorters in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Cell-Based AssaysCell-based assays are used to monitor the presence, quantity and activities of a desired cellular analyte including drug molecules or biomarkers. This can reveal information on cell health (apoptosis, cytotoxicity, viability and proliferation assays), cell metabolism, cell migration and cell signaling mechanisms. Find the best cell-based assay products, kits and equipment with our peer reviewed product directory: compare products, check customer reviews and receiving pricing direct from manufacturers.