Identifying high-affinity antibodies in human blood serum is a non-trivial task due to the extremely small number of circulating B-cells with the specified specificity. A team of scientists from the IBCh RAS proposed an effective approach that allows for the identification of high-affinity antibodies against pathogen proteins while simultaneously mapping epitopes, even in the absence of information about the structure of the pathogen's immunogens. To screen therapeutic antibodies in the blood of recovered donors, only the pathogen's transcriptome is needed to create a polypeptide library of antigens displayed on the surface of a bacteriophage. The work was published in the journal Communications Biology.