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The image below is an example of the experiments we perform to show our customers that our active recombinant proteins work in functional assays. Activin A and Wnt3a are just a few of the hundreds of cytokines, chemokines and growth factors that Abcam has to offer. Click here to browse our active proteins.
Specific activity level, or ED50, is listed on product datasheets (e.g. PD-L1), to assist you when selecting a protein for applications such as:
In addition, we provide data for applications such as standard curves for ELISA (e.g. TNF alpha), activity assays (e.g. MMP1), and binding ability (e.g. PD1). You will also find references on the pages of proteins that have been cited e.g. TGF beta 1 and BDNF.
Human embryonic stem cells (HUES4) were differentiated as monolayer cultures on matrigel coated dishes using a protocol described in Kroon et al, Nat Biotechnol. (2008). Activin A (ab50051) and Wnt3a (ab81484) were added to cultures to direct differentiation towards definitive endoderm. This image was taken 3 days after induction, where the definitive endoderm marker FOXA2 (ab40874 in green) is abundant. Dapi staining is shown in blue. Magnification: 200x. Negative controls of fluorescently conjugated secondary antibodies only showed no staining. Image courtesy of Emily Moorefield, Wake Forest Institute for Regenerative Medicine, NC, USA.
Whether it's for an ELISA, Western blot or flow cytometry experiment, we have thousands of native and recombinant proteins which can be used as experimental controls. To ensure you are selecting the appropriate product, our protein data sheets provide the following features:
Due to their quality and reliability, our proteins are ideally suited for use as positive controls or standards, ensuring your assays are repeatable. For example, our monoclonal IgE protein, ab65866 has been cited as an excellent standard for ELISA due to low batch-to-batch variability. If you need a specific batch, format, quantity or concentration for a set of experiments, just let us know and we will do our best to accommodate you.
We have a range of fluorescent proteins including GFP and proteins commonly used for detection such as Streptavidin-HRP. Ab7403 has been validated in immunohistochemistry staining systems and as an HRP label in a sandwich ELISA.
Fluorescent proteins can be fused to the N- or C- terminals of a broad variety of proteins, making them a useful non-invasive tag, detectable by fluorimetric analytical or imaging techniques. This means they can function as a cell lineage tracer or reporter of gene expression. Ab84191 is commonly used in western blot as a positive control to confirm the presence of GFP in fusion proteins.