although lymphocytes of some donors were `` '' low-responders '' '' under the above conditions , they responded to srbc when they were cultured with not only the antigen plus fresh human serum but also with the culture supernatant obtained after phytohemagglutinin ( pha ) stimulation of a mixture of pbl from two donors ( mlc-pha sup ) .
C0003320
e antig
C0024262
) stimulati