The relevance of the technology we present here is that it can be used to obtain monoclonal antibodies that are antigen specific, even when present only in low frequencies in humans. Indeed, direct isolation from the blood of influenza virus-specific B cells with a highly restricted B cell receptor repertoire has been described recently. However, healthy volunteers in this study had received booster vaccination against Influenza, inducing high percentages of antibody secreting plasma cells in the peripheral blood of these individuals [12] . Indeed, such abundance of antigen-specific plasma cells is unique. Much more often the frequency of antigen specific memory B cells is low, for example in cases where appropriate vaccines to induce such overt antibody response are lacking. In those instances the method described here may be applied to isolate human antigen specific monoclonal antibodies.