Question

which statement is true?
a) dapi is a blue fluorescent protein linked to an antibody that specifically binds dna
b) the coat proteins of the virus have fluorescent properties and appear red if they are excited with uv light
c) actin fibers will be green, because the dye linked to phalloidin absorbs green light
d) the filter cubes consist of an excitation filter, dichroic mirror and emission filter

Explanation:

• Option a: DAPI is a fluorescent dye, not a protein linked to an antibody, that binds DNA.
• Option b: Viral coat proteins do not inherently have red fluorescent properties under UV excitation; fluorescent tags are added.
• Option c: Actin fibers stained with phalloidin-linked dye appear green because the dye emits green light, not absorbs it.
• Option d: Fluorescence microscope filter cubes standardly contain these three components: excitation filter (selects excitation wavelength), dichroic mirror (reflects excitation light, transmits emission light), and emission filter (selects emitted fluorescence wavelength).

Answer:

d) The filter cubes consist of an excitation filter, dichroic mirror and emission filter