AP BIOLOGY

Detailed explanation-1: -Methylene blue is used to stain the nucleus while observing cheek cell. It has a strong affinity for both DNA and RNA which causes clear staining of nucleus and increases its visibility under microscope.

Detailed explanation-2: -What does methylene blue stain? Methylene blue, also known as methylthioninium chloride, can be used to stain or highlight parts of animal, bacteria, and blood tissue specimens in microbiology. Use it to closely observe the shapes, structures, and locations of dead cells and other tissues!

Detailed explanation-3: -Methylene blue-stains animal cells to make nuclei more visible.

Detailed explanation-4: -The methylene blue stain makes nuclei more visible although it stains both nuclei and cytoplasm; the eosin mainly colors the cytoplasm and cell membranes.

Detailed explanation-5: -Methylene blue is a cationic dye which is also known as basic dyes. It has a positive ionic charge so it will interact with cell nuclei that have a negative ionic charge of the tissue (4). This dye can react with anionic groups as phosphate groups of nucleic acids (DNA and RNA) which is commonly used as nuclear stains.