Allergic protein purification

“Allergens” are the substance that induces allergic reactions. Most allergens are proteins and some are a part of “hapten” (a small molecule that can elicit an immune response when attached to a larger carrier). Haptens alone cannot induce allergic reactions. It must bind with a carrier protein within body to induce an allergic reaction, such as a metal substance: nickel or chromium, or chemical substance: formaldehyde.

In place of using specific recombinant proteins (single sequence) in the traditional testing method, EBS has developed the “total allergen protein purification” technique. The basis of this technique is to screen each protein sequence, ensuring that no trigger allergens are overlooked and eliminating the possibility of inducing allergies.

With respect to each protein characteristic, we use molecular biology and proteomics techniques to design different protein purification strategies. As a result of these techniques, EBS currently holds nearly 200 types of common allergen proteins. Among them are the most common inhalation allergens such as mites, pollens, and animal fur, along with the most common ingestion allergens such as seafood, nuts, and milk.

Allergen activity validation and quality control

A stable allergy test depends on the stability of each batch of allergens produced. EBS has developed an integrated allergen activity validation and standard operating procedures for quality control, which include the following:


A. Safe and reliable allergen source :

Our main allergen suppliers are Greer and Allergon, which hold FDA and SS-EN ISO9001:2008 certifications respectively. EBS also has the capacity to extract our own allergens. All allergens extracted in-house are identified by species to verify their source and scientific name, then recorded and stored in quality controlled database.


B. Allergen stability :

Purification rating of each extraction batch is recognized by quantitative concentration and SDS-PAGE. This ensures the consistency of each allergen protein concentration and composition.


FLISA: Fluorescence-Linked Immuno-Sorbent Array

A. Microarray protein chip :

The foundation of the EBS microarray protein chip is based on using protein as probe markers which are spotted on the surface of a glass slide. To perform the test, serum sample is added to the test area creating an antigen-antibody binding reaction. A secondary antibody with fluorescent dye is then added to the surface allowing for specific wavelengths of the laser scanner to pin-point the specific antibodies induced by allergic reactions. Finally, three different concentrations of standard reagent are used to calculate the actual values and distributed over a standard curve to produce an accurate result.


B. Spotting system: BioDot AD3200

Our allergen protein chip uses the BioDot AD3200 Spotting system. This system uses a programmable robotic arm with a three-dimensional axis and specialized slit needles (using the “Siphon Theory”) to transfer the allergens onto the spotting surface.


C. Scan system :

EBS Specific IgE/G Allergy Tests utilizes the Axon 4100B laser scanner. By using a specific wavelength, the florescence dye which is bounded to a secondary antibody is excited and thus producing a special signal. We can then use the AxSys software to analyze florescence signals to generate an easy to read report in a short amount of time.

Compared to the traditional ELISA (Enzyme-linked immune-sorbent assay) allergy analysis, EBS’ allergy testing platform is systematicized by an innovative semi-automatic scanner and analysis software. The advantages of our platform are :

a. Minimal serum :
Lower amount of serum sample required.
b. Stability and sensitivity :
We conduct triplicate tests on each chip to ensure the stability of each batch. At the same time, we can detect the concentration limits (limitation can reach up to “pg” grade).
c. Environmentally-friendly and cost effective :
Small amount of reagents and consumables are used to perform the test, therefore lowering the consumption of resources.
d. High efficiency :
Multiple samples can be conducted simultaneously and the results are available within 1~2 hours.
e. High flexibility :
The FLISA platform allows for added flexibility of test items. As test items increase, the amount of serum sample and reagent can remain unchanged.