期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1973
卷号:70
期号:5
页码:1536-1539
DOI:10.1073/pnas.70.5.1536
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:RNA complementary to bulk humanplacental DNA was synthesized in vitro both in the presence and absence of 3H-labeled ribonucleotides. The 3H-labeled RNA was used directly for hybridization to the DNA of human metaphase chromosomes, whereas the unlabeled complementary RNA was labeled chemically with 125I before hybridization. A comparison of autoradiographs produced by either isotope revealed no qualitative differences in the chromosomal annealing sites of the same population of RNA molecules. Since 125I-labeled nucleic acids give similar, if not identical, results as do 3H-labeled nucleic acids in in situ hybridization experiments, their use should make possible the localization of genetic elements for which tritium labeling methods are either inadequate or not possible.
关键词:human placental DNA ; chromosomes ; metaphase ; autoradiography