4-MUNANA is a fluorescent substrate employed in neuraminidase activity assays and serves as a neuraminidase substrate analogue.

Instructions:
I. Solution preparation
1. Stock solution: Dissolve 4-MUNANA in a suitable buffer to prepare a stock solution with a concentration of 1–10 mM. The specific concentration can be adjusted according to the experimental requirements.
2. Working solution: Dilute the 4-MUNANA stock solution to a working concentration (usually 100–500 µM). The specific concentration can be adjusted according to the experimental requirements.
Notes:
Powder: Store at -20°C or lower in a dark, dry environment.
Stock solution: Store at -20°C in a dark place after aliquoting. Avoid repeated freezing and thawing. Store at 4°C for a short period of time.
II. Operation steps
Neuraminidase activity detection
1. Detection buffer: Prepare a buffer suitable for neuraminidase activity, such as 50 mM sodium acetate (pH 5.5).
2. Enzyme reaction: Mix a sample containing neuraminidase (such as a virus sample or cell lysate) with the 4-MUNANA working solution.
3. Incubate at 37°C for 30–60 Minutes (time can be optimized according to the experiment).
4. After the reaction is completed, add an equal volume of stop solution (such as 0.1 M glycine buffer, pH 10.4) to enhance the fluorescence signal.
5. Fluorescence detection
Detection method:
Use a fluorescence spectrophotometer or microplate reader to detect the fluorescence signal generated by the reaction.
Excitation wavelength: ~365 nm
Emission wavelength: ~450 nm
Notes
Standard curve: Use known concentrations of 4-methylumbelliferone to prepare a standard curve for quantitative analysis of neuraminidase activity.
Control experiment: Set up negative control (no enzyme) and positive control (containing known inhibitors) to verify the specificity of the detection.