title: Size heterogeneity of the structural units of brain nuclear ribonucleoprotein particles.
abstract: Nuclear ribonucleoprotein particles were examined by electron microscopy after negative staining. The results confirmed the polymeric nature of the particles. The constitutive units were distributed into 4 size classes (diameters varying from 100 to 300 A, approximately) indicating that the monoparticle population was heterogenous. When examined on ultrathin sections, the particles had a fibrillar appearance.
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002467:Cell Nucleus / Q000032:analysis* / Q000648:ultrastructure; D002499:Centrifugation, Density Gradient; D008854:Microscopy, Electron; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D009698:Nucleoproteins / Q000302:isolation & purification; D011132:Polyribosomes / Q000032:analysis; D011487:Protein Conformation; D012261:Ribonucleoproteins / Q000302:isolation & purification; D012270:Ribosomes / Q000032:analysis
chemical_list: D009698:Nucleoproteins; D012261:Ribonucleoproteins