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Antibodies are a key part of the adaptive immune system, and play a number of roles in nature and biotechnology. Antibodies are glycoproteins produced by B-cells that specifically bind a target antigen. An antigen is any substance (often a protein) that causes an immune response.
The primary antibody is what binds to your protein of interest. You must consider the location of the protein within the cell, intracellular or extracellular. Protein location will have a downstream effect on how you prepare your samples for protein detection. You must also consider the location of the epitope which the antibody binds to within that protein. The antibody will bind a specific contiguous sequence within the protein unless otherwise specified, which might be within the 3D conformation fold, and so the protein must often be in its denatured form for the antibody to bind the epitope. Some primary antibodies are raised using the full-length protein. These antibodies often don't recognize the unfolded, denatured version of the protein and bind epitopes on the 3D conformation of the protein surface, meaning that the epitope might be non-contiguous in the primary sequence. To find a primary antibody, use the search bar at the top of every page to search for your target or catalogue number. The search will use each term separately, so please type only the name of the target. To find out more about our search, please have a look at our purchasing support page or view a list of our primary antibodies.
The secondary antibody is what binds to your primary antibody. It serves to enhance the signal created by the primary antibody. Therefore, your secondary antibody will need to be against the host species used to raise your primary antibody. For example, for a primary rabbit polyclonal antibody, you could use a Goat Anti-Rabbit IgG antibody as a secondary. To find a secondary antibody, view a list of our available secondary antibodies and use the filter on the left to narrow down your results by target and conjugation.
The isotype control is used to view and remove background noise resulting from non-specific binding by your primary antibody. Your isotype control needs to match your primary antibody host, isotype and conjugation. For example, for a primary mouse IgG1 conjugated to FITC, you will need a mouse IgG1 isotype control conjugated to FITC.
Aliquoting and storing will depend on the volume needed and the frequency of use respectively. We recommend aliquoting the sample in 10 µl and storing at -20 °C in the freezer. Once the sample is defrosted, keep at 4 °C in the fridge to avoid too many freeze/thaw cycles, as this will affect the antibody's effectiveness. For more information, please have a look at our antibody storage page.
This will depend on how closely related is the target species to your species of interest. You can obtain the different protein sequences from UniProt and check the sequence mapping using the analysis tool. Alternatively, quickly check whether the epitope of your antibody matches a sequence of the untested species.
We can provide most immunogen sequences. Some immunogen sequences, however, are propietary. In cases where there is propietary conflict, we will offer you information on the area of the protein where the antibody binds.
The applications that a product has been tested in are listed on the product page and datasheet. For untested applications, we generally recommend purchasing a small quantity and conducting a pre-test to determine the suitability for your needs.
The concentration used will depend on the application the antibody is being used for and the expected concentration of the target protein. For WB and FCM you should use a concentration of 1 μg/ml. For IHC and IP you should use a higher concentration, starting at 5 μg/ml. For ELISA, start with 0.1 μg/ml. These numbers are a guide, you should always optimize concentration for your particular experiment so that you obtain the best affinity binding without much background binding.
