Chromosome Banding
and Staining Techniques
Exam Questions and
Complete Solutions
Graded A+
Denning [Date] [Course title]
, What type of replicating DNA is positive heteropyknosis? - Answer: Late replicating DNA
What are some characteristics of positive heteropyknosis? - Answer: dark G and Q bands, light R bands,
C bands, late replicating, positive heteropyknosis, heterochromatin, inactive, A-T rich
What type of replicating DNA is negative heteropyknosis? - Answer: early replicating DNA
What are some characteristics of negative heteropyknosis? - Answer: light G and Q bands, dark R
bands, early replicating, negative heteropyknosis, euchromatin, active, C-G rich
What is the chromosome banding code? - Answer: first letter=type of banding, second letter=general
technique used, third/last letter=stain used
GTG - Answer: G banding by trypsin using Giemsa stain
QFQ - Answer: Q banding by fluorescence using quinicrine dihydrochloride or quinicrine mustard
RFA - Answer: R banding by fluorescence using acridine orange
RHG - Answer: R banding by heat using Giemsa stain
CBG - Answer: C banding by barium hydroxide using Giemsa stain
Who discovered G banding and in what year? - Answer: Seabright in 1971
Who discovered Q banding and in what year? - Answer: Caspersson in 1970
Who discovered R banding and in what year? - Answer: Dutrillaux and Lejeune in 1971
Who discovered C banding and in what year? - Answer: Arrighi and Hsu in 1971