Which fluorochrome emits red light at a wavelength of 580 nm?

Tetramethylrhodamine isothiocyanate is a fluorochrome that is known for emitting red light, specifically at a wavelength of around 580 nm. This property makes it valuable in various applications, including fluorescence microscopy and flow cytometry, where distinguishing between closely related signals is crucial. Tetramethylrhodamine isothiocyanate binds well to proteins and can label antibodies, allowing researchers to visualize specific proteins or cells in experiments.

The context of fluorescence in immunology and other scientific fields often involves using different fluorochromes, each with distinct emission wavelengths. The ability to select a fluorochrome that emits at a precise wavelength helps in multiplexing experiments, where multiple targets can be detected simultaneously. In this case, the specific emission wavelength of approximately 580 nm for tetramethylrhodamine isothiocyanate is why it is the correct choice for this question.