Answer: Methylene blue can be used to stain DNA of a cell because it (forms ionic bonds with DNA).
Explanation:
To examine the components of a cell usually under a microscope, a stain or dye is being used to provide a clear and defined view of the area under study.
The deoxyribonucleic acid (DNA) of a cell which contains the hereditary information of the cell is located in the nucleus.
Methylene blue is a type of stain used by biologists which helps them view microscopic life in brilliant color. It is a cationic stain (positively charged blue dye); and binds to negatively charged parts of the cells, such as nucleus (DNA) and RNA in the cytoplasm (with lower affinity).
When DNA of a cell comes in contact with methylene blue on a slide, their opposite charges attract, causing methylene blue's "rings" to slide in between the "rungs" of the DNA "ladder." As a result, a rich blue stain that identifies the location of the cell nucleus can be observed. This produces a photosensitive reaction which can then be viewed under the microscope.
Therefore is can be used to stain the DNA of cell because it forms ionic bonds with DNA.
