Nature, India ink (or Congo red, nigrosin) stains the background dark. This is a negative staining technique that isĮssentially used to identify the presence of capsules. However, some of the other stains that can also be used include: India ink is often used as the negative stain. Spread out the drop into a film to have a thin layer of the smear-ink mixtureĬrystal violet for a minute and then tilt the slide to drain excess dye Glass slide and having laid it at an angle on one end of the first slide, Obtain a sample and place it onto the slide and mix it with the drop of India Two of the most commonly used methods used in It becomes necessary to stain the background using an acidic stain while the It's worth noting that for most part, capsules are non-ionic.Īcidic and basic stains will often fail to adhere on to them. Which involves the use of two stains primary stain and the counterstain. Some of the organisms that are likely to have aĬapsule stain is a type of differential stain Some of the other significance of a capsule

This is achieved due to the fact that the capsule is very smooth and has a negative charge that prevents attachments/adherence. For some bacteria, capsules are very important in that they are a major virulence factor.Īs such, they protect the bacteria from phagocytic actions of such cells as neutrophils allowing the bacteria to thrive. They may also be composed of a number of other materials such as poly-D-glutamic acid. Typically, a capsule is composed of capsular polysaccharides (CPS) which are polysaccharides. Monochrome Staining – Principle, Procedure and Result | Biology Ideas

India ink red