Staining enhances contrast so that structures in a sample can be seen and distinguished, especially under a microscope. This lesson introduces the purposes of staining, the kinds of samples it can reveal, and how stains support biological and materials research.
Many cells and tissues are nearly transparent. A stain adds colour or another detectable signal, making selected structures easier to observe. In histology, staining helps examine tissues; in cytology, it helps examine cells. Histopathology, hematology, and cytopathology use stained samples to study and diagnose disease.
All flashcards
What is staining?
A technique that adds colour or another detectable signal to enhance contrast and make selected sample features easier to observe.
What does histology study?
Histology is the microscopic study of biological tissues.
How does simple staining differ from differential staining?
Simple staining uses one stain at a time. Differential staining uses multiple stains or reagents to make structures with different properties appear distinct.
Name two uses of staining beyond viewing tissue sections.
Staining can mark cells for flow cytometry and reveal proteins or nucleic acids in gel electrophoresis. It can also be used to study materials such as polymers.
What is a counterstain used for?
A counterstain adds contrast to cells or structures that are not sufficiently visible with the principal stain.
Quiz questions
What is the typical result of Gram staining for Gram-positive bacteria?Answer: They retain crystal violet and appear purple.
Why is heat used in a commonly described endospore staining method?Answer: It helps the dye penetrate resistant endospores.
What is the Ziehl–Neelsen stain especially useful for detecting?Answer: Acid-fast bacteria such as Mycobacterium tuberculosis.
In H&E staining, what does haematoxylin typically stain blue?Answer: Cell nuclei.
What does BSC certification of a biological stain indicate?Answer: Independent testing of purity, dye content, and performance.
Based on the Wikipedia article Staining, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.