Nuclear RNA in the mouse spleen at the peak of primary immune response.

Electrophoretic studies on nuclear RNA extracted from the spleens of immunized mice are reported. RNA was extracted by the phenol-detergent procedure from the purified nuclei of spleen cells at the peak of primary immune response after a single immunization with sheep red blood cells. The kinetics of labeling in vivo with 32P-orthophosphate indicate an accelerated biosynthesis of the ribosomal RNA precursors, 28S, 18S, 5S and 4S fractions of nuclear RNA in the spleens of immunized mice.