Select antigen as a product subtype, or immunization as an application
When your research requires an antigen, perhaps to develop a new antibody or to block an existing immunoglobulin, there are a couple strategies to finding suitable reagents. Firstly, you can apply the antigen product subtype from the product type filter to home in on products that are likely to have been labelled an antigen by vendors. Alternatively, you can filter by immunization as the application.
Furthermore, you can add the sequence filter under Protein specs to limit your results to products with a known amino acid sequence.