Question

multiple choice question
which of the following is used to stain a specimen that will emit a different wavelength of light than it absorbs?

crystal violet
india ink
fluorochrome
heavy metal

Explanation:

Fluorochromes are fluorescent stains that absorb light at one wavelength and emit light at a longer, different wavelength (a property called fluorescence). Crystal violet is a basic dye used for simple/gram staining, India ink is used for negative staining, and heavy metals are used for electron microscopy staining, none of which exhibit this light absorption-emission wavelength shift.

Answer:

Fluorochrome