Groove-binding unsymmetrical cyanine dyes for staining of DNA: dissociation rates in free solution and electrophoresis gels.
The rates of dissociation of three non-intercalative unsymmetrical cyanine dyes, BEBO, BETO and BOXTO from mixed-sequence DNA have been studied with the DNA either free in solution or in confining porous agarose gels. The properties of the new dyes were compared to the related intercalating dyes BO, BO-PRO, TO-PRO and YO-PRO. With DNA in solution, BEBO dissociates more slowly than the monovalent BO and interestingly also more slowly than the divalent dye BO-PRO. Similarly, both BETO and BOXTO exhibit considerably slower dissociation than TO-PRO. The new dyes show biexponential dissociation kinetics in mixed-sequence DNA. The average rate of dissociation increases with increasing ionic strength, but the salt dependence of the dissociation is weaker than for the corresponding intercalating dye. The rate of dye-dissociation decreases by a factor of about 10(5) in the gel. The rates for the dyes generally follow the pattern that we observe with the DNA in free solution, however a more accentuated stabilization was seen for intercalators than for groove-bound dyes. The results show that, in particular, BOXTO is a promising candidate as a preferentially groove-bound DNA-stain with a large enhancement of the fluorescence quantum yield upon binding to DNA, and which exhibits slow and salt-insensitive dissociation compared to corresponding intercalative dyes.
Department of Chemistry and Bioscience, Chalmers University of Technology, S-412 96 Gothenburg, Sweden.
Maja
M
Eriksson
H Jonas
HJ
Karlsson
Gunnar
G
Westman
Björn
B
Akerman
D000818:Animals; D052160:Benzothiazoles; D002232:Carbocyanines / Q000737:chemistry* / Q000378:metabolism*; D002417:Cattle; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism*; D007364:Intercalating Agents / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D015394:Molecular Structure; D011726:Pyridinium Compounds / Q000737:chemistry / Q000378:metabolism; D011806:Quinolinium Compounds / Q000737:chemistry / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D012996:Solutions / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism
C473386:4-((3-methyl-6-(benzothiazol-2-yl)-2,3-dihydro- (benzo-1,3-thiazole)-2-methylidene))-1-methyl-pyridinium iodide; C479411:4-(6-(benzothiazol-2-yl)-3-methylbenzothiazolyliden-2-yl)-1-methylquinolinium; C479412:4-(6-(benzoxazol-2-yl)-3-methylbenzothiazolyliden-2-yl)-1-methylquinolinium; D052160:Benzothiazoles; D002232:Carbocyanines; D005456:Fluorescent Dyes; D007364:Intercalating Agents; D011726:Pyridinium Compounds; D011806:Quinolinium Compounds; D012996:Solutions; D013844:Thiazoles; D012965:Sodium Chloride; D004247:DNA