Open AccessHigh‐resolution R‐banding at the 1250‐band level
Author(s) -
DROUIN RÉGEN,
LEMIEUX NICOLE,
RICHER CLAUDELISE
Publication year - 1991
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1991.tb00554.x
Subject(s) - biology , giemsa stain , karyotype , chromosome , resolution (logic) , mitosis , microbiology and biotechnology , genetics , gene , artificial intelligence , computer science
High‐resolution human chromosomes were oblained from lymphocytes after thymidine synchronization. The block was released either with thymidine to produce GTG (G‐bands by trypsin using Giemsa) and RHG (R‐bands by heating using Giemsa) banding or with BrdU (5‐bromo‐2′‐deoxyuridine) for RBG (R‐bands by BrdU using Giemsa) banding. RHG and RBG band patterns are only 75 to 85 % congruent. The dissimilarities increase with the band number per genome and vary from one chromosome region lo another. After high‐resolution RBG banding, the BrdU‐substituted bands show an unequal condensation delay, which can be, according to the bands involved, very important, minimal, or even absent. The bands showing the highest degree of condensation delay are the bands replicating the latest. The GTG‐ and RHG‐band patterns show complementary matching for about 90 % of the bands. It was found that two third of the chromosome surface appears positively stained after R‐banding. This suggests that more DNA is replicated during early S‐phase than during late S‐phase. To obtain a fully developed RBG‐band pattern in 90 to 95 % of harvested mitoses, a period of 4.5 hours after the removal of the blocking agent is optimal. Such a brief release period also implies that late S‐phase is much shorter than early S‐phase.