title: Immunological assay of double-helical segments in RNA fractions of different molecular size extracted from acute myeloid leukemia blast cells.
abstract: Whole-cell RNA, extracted from acute myeloid leukemia blast cells, was fractionated by sedimentation through sucrose gradients. The proportion of double-helical segments present in each fraction was then determined by a quantitative microcomplement fixation assay that specifically measures double-helical RNA. Sizable amounts of double-helical segments were detected in all fractions of cellular RNA corresponding to S values higher than approximately 20. In all cell populations examined the highest proportion of double-helical segments was found in RNA fractions sedimenting faster then the 45 S ribosomal precursors RNA, i.e., in  fractions including only heterogeneous nuclear RNA.
mesh_terms: D000918:Antibody Specificity; D000951:Antigens, Neoplasm; D002467:Cell Nucleus / Q000032:analysis; D002499:Centrifugation, Density Gradient; D003168:Complement Fixation Tests; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D006801:Humans; D007074:Immunoglobulin G; D015470:Leukemia, Myeloid, Acute / Q000032:analysis*; D008832:Microchemistry; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D012334:RNA, Neoplasm / Q000032:analysis* / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D000939:Epitopes; D007074:Immunoglobulin G; D012334:RNA, Neoplasm