9-Aminoacridine: an efficient reagent to improve human and plant chromosome banding patterns and to standardize chromosome image analysis.

Background: Successful automated chromosome analysis requires the development of new techniques to increase and standardize chromosome length and improve banding patterns.

Methods: Human and plant cells were pretreated with the DNA intercalator 9-aminoacridine (9-AMA), and chromosomes were stained with GTG and aceto-orcein banding techniques and investigated by an image analysis system.

Results: The human optimal chromosome spreads with the 850 G-band resolution level, suitable for image analysis, were obtained by 9-AMA pretreatment for 1 h at a final concentration of 0.5-1 microg/ml, as compared with 600-700 bands after ethidium bromide treatment and about 400 bands without pretreatment. The best results for plant chromosomes were obtained after pretreatment with 1-2 microg/ml of 9-AMA for 12-24 h. The chromosomes elongated approximately 1.5-fold, and the resolution of chromosome banding patterns increased, reaching approximately 140 bands per haploid set in the case of camomile.

Conclusions: 9-AMA is an efficient reagent for the standardization and increasing the resolution of chromosome banding patterns in human and plant chromosomes. It is extremely important for chromosome investigation in small plants.