RayBiotech Quantibody Technology

The Quantibody array is a multiplex, sandwich-based ELISA (Enzyme Linked Immunosorbant Assay), designed to measure the concentration of multiple cytokines in one experiment.  Like a traditional sandwich-based ELISA, it uses a pair of cytokine specific antibodies for detection.  However, Quantibody takes this method of analysis to another level.  By arraying multiple specific capture antibodies onto a glass support, multiplex detection and quantification of cytokines in one experiment is made possible.

Each item in the Quantibody product line has been tested to have similar or better detection sensitivity than traditional ELISA.  Reproducibility and sensitivity is bolstered by use of a photobleaching resistant Alexa dye.  Moreover, because we use an open format glass slide as our substrate, dozens or even hundreds of antibodies can be arrayed on the same array.  

RayBiotech custom Quantibody arrays allow users to choose their own panels for cytokine detection.  RayBiotech has tested and used the highest affinity antibodies possible on the market, and each pair has been especially optimized for maximum sensitivity.

Sensitivity depends on the binding affinity of the antibody-antigen complex, which can vary for each cytokine.  Scientists at RayBiotech test for the highest possible affinity, and each pair has been especially optimized for maximum sensitivity.  Moreover, for the system itself, Quantibody products have been tested to have similar or better detection sensitivity than traditional ELISA.

By comparing each cytokine with serial dilutions of predetermined concentrations of array specific cytokine standards on the same array, it is possible to generate fully quantitative data using Quantibody.

Quantibody arrays can accommodate many different types of sample: cell culture supernatant, serum, plasma, tissue lysate, and other body fluids.  Typically, all that’s necessary is 50-100ul per sample for one array.  The following parameters can be used for samples volume: 50-100μl of cell culture supernatant, 50-100μl of original or diluted serum or plasma; or 20-200μg of protein for cell lysates and tissue lysates. For those samples in which a high response for one cytokine is expected, while a low response is expected for another, we recommend testing each sample in stepwise dilutions.

Frequently Asked Questions about Quantibody

What kind of samples can be detected with Quantibody kits? and How much sample do I need for the experiment?

Quantibody arrays can be used in cell culture supernatant, serum, plasma, CSF, tissue lysate, and other body fluid. Typically, 50-100 μl samples are needed for one array.

We recommend the following parameters for your samples: 50-100 μl of cell culture supernatant, 50-100 μl of original or diluted serum or plasma; or 20-200 μg of protein for cell lysates and tissue lysates. In order to minimize the matrix effects and to lower the background of the assay, we recommended that the samples are at least diluted 2 fold with Sample Diluent. Dilute the lysate at least 5 fold with Sample Diluent to make a total volume of 50 to 100 μl. For those samples in which you expect a high response for one cytokine and a low response for another, we recommend testing each sample in step dilutions. For example, when testing cell culture supernatant for unknown cytokine concentrations; a 1:2, a 1:10, and a 1:50 dilution are typically used.

What cytokine standards are used in the Quantibody Array?

Laboratories throughout the world use different bioassays and immunoassays to determine cytokine concentrations.  As a result, the reported cytokine concentrations in the same sample may vary when using different ELISAs developed by different labs. For this reason, the availability of international standard preparations of cytokines is essential to allow definitive analysis and comparison of results. Quantibody Arrays use either our internal cytokine standards or the International Biological Standards from the National Institute for Biological Standards and Control (NIBSC), the gold cytokine standards.

 Is there any cross-reactivity between the cytokines?

For the available kits, no. . We have tested all of the available antibodies with their specific purified antigens for the cross-reactivity. The antibody pairs used in the kit have been tested to recognize their specific cytokines. There may be some cross-reactivity between antibodies included in two different kits, but analysis of samples containing only a single recombinant cytokine found no cross-reactivity with other antibodies in the same array. For the custom arrays, we will suggest what cytokines can be included in the same array to ensure the proper level of specificity and sensitivity.

References

Ray S, Britschgi M, Herbert C, Takeda-Uchimura Y, Boxer A, Blennow K, Friedman LF, Galasko DR,

Jutel M, Karydas A, Kaye JA, Leszek J, Miller BL, Minthon L, Quinn JF, Rabinovici GD, Robinson WH,

Sabbagh MN, So YT, Sparks DL, Tabaton M, Tinklenberg J, Yesavage JA, Tibshirani R, Wyss-Coray T  (2007)  Classification and prediction of clinical Alzheimer's diagnosis based on plasma signaling proteins.  Nat Med:11 1359-62

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Please click here for more information and pricing on RayBiotech’s Custom Quantibody Array Testing Services.

Please click here for more information and pricing on RayBiotech’s Quantibody Array kits

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