N-(2-hydroxyethyl)-Naphthalimide is a fluorescent probe for nucleic acid detection whose fluorescence can be burst.

I. Application in nucleic acid detection
1. Material preparation
(1) HEN probe: dissolved in an appropriate organic solvent (such as DMSO or ethanol), the recommended concentration is 1-10 µM.
(2) Sample: extracted DNA/RNA, or single-stranded nucleic acid for in vitro synthesis (such as specific oligonucleotides).
(3) Buffer: buffer suitable for nucleic acid reaction (such as Tris-HCl, pH 7.5).
2. Experimental steps
(1) Establishment of fluorescence detection system:
Prepare the reaction system, including HEN probe and target nucleic acid, and ensure uniform mixing.
The binding of probe to nucleic acid can quench the fluorescence signal by forming a complex or changing the surrounding environment.
(2) Fluorescence signal monitoring:
Record the change of fluorescence intensity on a fluorescence spectrometer, the excitation wavelength is usually 350-400 nm, and the emission wavelength is 450-500 nm.
Evaluate the nucleic acid concentration or reaction kinetics by the change of fluorescence signal.
(3) Nucleic acid comparison experiment:
Compare the target nucleic acid sequence with the non-specific nucleic acid sequence to verify the selectivity and specificity of the probe.
c. Data analysis
Use the change in fluorescence signal intensity (or quenching efficiency) to draw a fluorescence titration curve, and calculate the concentration of the target molecule by nonlinear fitting.
2. Fluorescence imaging
Experimental steps:
(1) Load the HEN probe into the cell culture medium and incubate with living cells.
(2) Use a fluorescence microscope to observe the distribution of the probe in the cell nucleus or cytoplasm and record the fluorescence intensity.
(3) For specific nucleic acid targets, control experiments can be performed by adding RNA/DNA enzymes to verify the binding specificity of the probe.