Only intercalating ions cause the temperature sensitivity in acridine orange-stained artificial nine-plasmid system-2

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Acridine orange (AO) is a fluorescent dye used for staining nucleic acids.
• Temperature sensitivity in molecular assays can affect experimental outcomes.
• Understanding ion effects on dye-DNA interactions is crucial for assay optimization.

Purpose of the Study:

• To investigate the influence of various ions on the temperature sensitivity of AO-stained DNA.
• To identify specific ions that induce temperature sensitivity in an AO-stained nine-plasmid system.
• To correlate ion properties with observed temperature sensitivity.

Main Methods:

• Electrophoresis of a nine-plasmid system on agarose gel at different temperatures (5°C and 25°C).
• Post-staining with AO solutions containing various ions (Tris, AMPD, etc.).
• UV-Vis absorption and fluorescence spectroscopy measurements across a temperature range (5°C-45°C).
• Statistical analysis using ANOVA for intergroup comparisons.

Main Results:

• Tris-AO and AMPD-AO solutions induced temperature sensitivity in the AO-stained nine-plasmid system.
• Significant fluctuations in optical signal intensity with temperature were observed for Tris-AO and AMPD-AO.
• The number of DNA bands after electrophoresis varied with Tris and AMPD at 5°C.
• Other ions did not induce temperature sensitivity but reduced AO staining.

Conclusions:

• Organic weak base cations like Tris and AMPD induce temperature sensitivity in AO-stained DNA systems.
• This temperature sensitivity is linked to the interference of these ions with AO intercalation into DNA.
• Ionic strength positively correlates with the observed temperature sensitivity.