t-lymphocyte colonies can be obtained from normal human peripheral blood and bone marrow , using a double layer technique which requires the simultaneous presence of peripheral blood irradiated leucocytes in the underlayer and phytohaemagglutinin in the overlayer ( foa & catovsky , clin . exp . immunol. , 36 , 488 , 1979 ) .
C0229664
peripheral blood
C0023516
leucocytes