Which property is NOT a feature of Alexa Fluor dyes?
Alexa Fluor dyes were developed as superior alternatives to fluorescein and rhodamine, offering exceptional photostability for prolonged imaging, high molar extinction and quantum yield, good solubility, pH insensitivity across physiological range, and suitability for fluorescence resonance energy transfer when spectrally matched. However, they do not possess particularly narrow emission peaks comparable to quantum dots or some BODIPY derivatives; their emission spectra remain relatively broad with characteristic tails. This breadth increases risk of channel crosstalk in multiplexed experiments, requiring careful filter selection and linear unmixing to avoid bleed-through during quantitative multi-color analysis.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.