Nucleic Acid Specificity, Cellular Localization and Reduced Toxicities of Thiazole Orange-Neomycin Conjugates

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Probes

Background:

• Selective binding of small molecules to nucleic acids is crucial for cellular analysis.
• Thiazole orange is a fluorescent dye for nucleic acid binding but can be cytotoxic.
• Neomycin binds nucleic acids but has poor cell permeability.

Purpose of the Study:

• To develop a less cytotoxic, cell-permeable fluorescent probe for RNA.
• To conjugate neomycin with thiazole orange to combine their properties.
• To evaluate the new conjugate for cellular labeling and nucleic acid stabilization.

Main Methods:

• Chemical conjugation of neomycin and thiazole orange.
• Assessment of cell permeability and cytotoxicity.
• Microscopic imaging for intracellular localization, focusing on nucleolar RNA.
• Measurement of nucleic acid denaturation temperature to assess stabilization.

Main Results:

• The thiazole orange-neomycin conjugate demonstrated increased cell permeability compared to neomycin alone.
• Cytotoxicity of thiazole orange was reduced in the conjugated form.
• The conjugate showed enhanced localization in the nucleolus, targeting intracellular RNA.
• Conjugated compounds significantly increased nucleic acid stabilization, indicated by higher denaturation temperatures.

Conclusions:

• Conjugated thiazole orange-neomycin compounds offer a less cytotoxic and more effective alternative for cellular RNA labeling.
• This approach enhances the utility of fluorescent probes for microscopic imaging.
• The improved properties facilitate advanced cellular analysis and nucleic acid studies.