Dear Mr. Cao,
Welcome to our forum!
You write that you want to detect pesticides and antibiotics using ELISA, we don’t have any ELISAs or antibodies that can be used for this. Our focus is cytokines, immunoglobulins and apolipoproteins.
I can give you some general ELISA information. First I think you should visit our assay principle section on our website, it is very informative and can guide you in how an ELISA assay is working: https://www.mabtech.com/knowledge-center/assay-principles/elisa-assay-principle
ELISA is an immunoassay that enables sensitive quantification of analytes in solution e.g. cell supernatants, plasma, serum, CSF, saliva etc. The assay relies on the antibodies that capture and detect the analyte of target, and the antibodies’ affinity, avidity and antigen interactions are essential for the quality of the assay. There are different types of ELISA’s, but we at Mabtech utilized Sandwich ELISA as this is the most sensitive ELISA assay.
To set up a Sandwich ELISA you need:
· ELISA plates, high protein binding plates, there are several different available, Corning and Nunc are examples of two brands that have this kind of plates.
· An antibody pair with specificity against analyte you are interested in. Preferably, the antibody pair should have been validated for ELISA.
The antibody pair should contain one capture antibody and one detection antibody. If the detection antibody is biotinylated you will also need an enzyme conjugate like Streptavidin-HRP. Streptavidin binds to the biotin part on the antibody. We have SA-HRP conjugates (link here). Some detection antibodies are directly conjugated with an enzyme e.g. HRP, then the SA-HRP conjugate is not needed.
· A substrate that reacts with the enzyme. In the above examples, I have mentioned HRP, and a substrate that reacts with HRP is the TMB ELISA substrate (link here).
· TMB substrate needs to be stopped with e.g. H2SO4 (0.2M).
· An ELISA reader that can measure the absorbance.
· Apart from this you also need several buffers, what buffers that should be used is dependent on the analyte and the antibodies, therefore I cannot recommend any specific. In our ELISAs these are the most common buffers: Coating buffer (PBS pH 7.4). Washing buffer (PBS pH 7.4 with 0.05% Tween), blocking/incubation buffer ( PBS pH 7.4 with 0.1% BSA and 0.05%Tween20) for blocking and dilution of antibodies and samples.
I hope this can give you some advice! Good luck!
Lena Beckman