Raybiotech - Quantibody

INTRODUCTION
 

Quantibody® array is multiplex system based on sandwich ELISA principle. It allows simultaneous quantitative cytokines detection in various samples - serum, plasma, CSF, cell lysate, medium or another fluid. This method combines advantage of high detection specifity and sensitivity of ELISA method and the possibility to determine large variety of cytokines together as in the case of antibody arrays.

 

As same as in traditional sendvich ELISA method, we use pair of specific antibodies for cytokine detection. Capture antibody is bound to a normal microscope glass surface. After incubation with the sample, the cytokine is bound to capture antibody. In the next step, the biotinylated detection antibody is bound to the cytokine, it is targeted to another cytokine epitope. The cytokine-antibody-biotin complex can be visualised by adding streptavidin-labeled fluorescent dye. Fluorescent signal can be easily detected by means of laser scanner.

The standard microscopic glass is used, that is big difference between Quantibody Array and ELISA method. On the microscopic glass, the 16 identical fields are placed, we call them protein chip and they contain positive and negative control and up to 40 kinds of cytokines in quadruplets. If we place 4 glasses into a special frame, we can now work with 64 protein chips at one time. This format is great for robotic processing.
 

 

For cytokine quantification we use defined mixture of cytokine standards. The mixture is gradually dilluted and we place it into the first 5 field (chips) on the glass to make 5-point calibration curve for each of cytokine determined. During the experiment, the samples and standards are analyzed simultaneously on the basis of ELISA method. By comparing the signal of sample with calibration curve we are able to calculate the cytokines concentrations in the sample.
 

 

WHY TO USE QUANTIBODY ARRAY?

 

1) Less of the sample, but more data:

 

For up to 40 cytokines quantification only 50 µl of sample is necessary. This method is 80 times more effective than conventional ELISA. This great advantage would be appreciated by those, who work with rare or expensive samples.

 

2) Less time consumed

 

Evaluation of one glass lasts about 4 hours. Because of automation of this method, the hundreds of samples can be analyzed during only one day. 

 

3) ELISA - detection sensitivity

 

ELISA is well known because of its sensitivity and specificity during cytokine quantification. Because Quantibody array method are on the basis of sandwitch ELISA, it can benefit from its high sensitivity.

 

4) Reproducibility

 

In Quantibody kits, Alexa fluorescent dye is used. This dye is known by its great endurance against lowering the signal intensity because of the light exposure. This feature guarantee high reproducibility of the kit. Glasses can be scanned multiple times. If we are able to keep them stored in a dark, cold environment ( -30°C and less), fluorescent dye will withstand many months or years without losing its intensity or sensitivity.

 

5) Flexibility

 

Custom build Quantibody arrays are very popular. Today you can choose from over 500 of various cytiokines and you can choose detection colour as well (e.g. Alexa 647 - red cy5 or Alexa 555 - green cy3). The basic overview of molecules: (molekuly_quantibody.xls)

 

6) Software for data quantitative analysis

 

It is very profitable to use data analysis software Q-analyzer from RayBiotech company. Program is based on excel format and it is very easy to use. Data which we obtain from laser scanner we will copy into Q analyzer software and program will perform all necessary calculations and graphs by itself.

 

7) Laser scanner

 

For fluorescent signal detection we use laser scanner. The main advantage is easy manipulation and minimal maintenance. Scanner is used for reading the antibody arrays and gene microarrays as well. If you don´t have this device, we will gladly read your glasses on our scanner and we will send you evaluated data. High stability of fluorescent signal allows easy transport of evaluated glasses. Best method for transport them is to keep them in a tube, pack them into aluminium seal, put it into an envelope and we will pick them up by ourselves or by courier company.

 

8) Send us your samples and we will sent you results

 

If you want to, we can evaluate your samples and send you final results. Please ask for prices and for all informations.

 

 

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