IMMUNOELECTRON MICROSCOPY OF RNA COMBINED WITH NUCLEIC-ACID CYTOCHEMISTRY IN PLANT NUCLEOLI

The immunoelectron microscopy detection of RNA using anti-RNA monoclon al antibodies has been performed for the first time over different pla nt cells. The use of the methylation-acetylation (MA) method permits c lear distinction among the nuclear and nucleolar compartments and can be combined with the immunogold approach. Cytochemical methods for nuc leic acids were performed together with the immunoassays, providing ad ditional data about the different composition of the various nucleolar components. Anti-RNA antibodies highly labeled the ribosome-rich area s of the cytoplasm and the nucleolus. The interchromatin region also i s labeled. The labeling was intense in the granular component, lower i n the dense fibrillar component, and very scarce in the fibrillar cent ers. The MA method made possible the statistical evaluation of the lab eling density in the various nuclear compartments by permitting the cl ear assignment of the particles to precise nuclear structures. (C) 199 4 Academic Press, Inc.