The general term is 'stain' of which there are several chemicals that can be used, depending on the specimen.
Stains.
Chemicals such as dyes, stains, or fixatives are commonly used in specimen preparation to make them more visible under a microscope. Dyes bind to specific cellular components, stains highlight certain structures, and fixatives preserve the specimen's morphology for observation.
A meteor, sometimes incorrectly called a shooting star or falling star.
Water is sometimes called H2O, as it is a chemical compound made up of two hydrogen atoms and one oxygen atom.
The morning star. Even though it is not a star, and even though it is not always visible in the morning, and is often visible in the evening. -- additional answer -- It is often called "the evening star" also.
Stains.
When a visible chemical haze is in the atmosphere it can be called a toxic cloud or nuclear fallout. This depends on the type of chemical that has been disbursed into the air.
Chemicals such as dyes, stains, or fixatives are commonly used in specimen preparation to make them more visible under a microscope. Dyes bind to specific cellular components, stains highlight certain structures, and fixatives preserve the specimen's morphology for observation.
immersion oil
That is called visible light.That is called visible light.That is called visible light.That is called visible light.
A meteor, sometimes incorrectly called a shooting star or falling star.
That is called visible light.That is called visible light.That is called visible light.That is called visible light.
A __________ mark is sometimes called a nonprinting character because it can be displayed on the screen but is not visible on a printed document.
Water is sometimes called H2O, as it is a chemical compound made up of two hydrogen atoms and one oxygen atom.
Mitochondria
The morning star. Even though it is not a star, and even though it is not always visible in the morning, and is often visible in the evening. -- additional answer -- It is often called "the evening star" also.
In covalent chemical bonds sometimes the electrons are loosely called "covalent electrons" as they are localised.