Online Microbiology and Biology Notes
What is positive staining? Positive staining of viruses is similar to negative staining. The difference is that the virus image is darker formed on a light background, unlike the negative staining where a light viral particle image is formed on a dark background. The technique is simple and it is used widely to study the diverse morphologies of viruses from …
What are the Romanowsky Stains? Romanowsky Stains are the stains that are used in hematology and cytological studies, to differentiate cells in microscopic examinations of blood and bone marrow samples. These stains are also applied to detect the presence of parasites in the blood such as malaria parasites. There are various Romanowsky staining types that apply the same principle. They …
What is Periodic Acid-Schiff (PAS) Staining? Periodic-Acid Schiff (PAS) staining technique is used in histochemistry and histological studies to demonstrate the presence of carbohydrates and carbohydrate compounds such as polysaccharides, mucin, glycogen, and fungal cell wall components. It has been used to detect glycogen in tissues such as the skeletal muscles, the liver, the cardiac muscles. It uses formalin-fixed, paraffin-embedded …
What is the Negative staining of Viruses? Staining techniques are designed to show contrast under microscopic observation. The staining of viruses is done to increase the contrast between the virus and the background. The use of an electron microscope intensifies the density of electron toward the stain. Negative staining is one of the most excellent techniques in studying viruses, bacterial …
What is silver staining? Silver staining is a special yet powerful staining technique that is used for the detection and identification of proteins in gels. This is because silver binds to the chemical terminal or side chains of amino groups i.e carboxyl and sulfhydryl groups. It has been used for decades now to separate proteins from polyacrylamide gel electrophoresis. The …
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What is Collagen Hybridizing Peptide Staining? Collagen is the major building block of all tissues including tendon, ligament, cornea, cartilage, and bone It is a fibrous, structural protein that made up of a right-handed bundle of three parallel, left-handed polyproline II-type helices. Collagen can undergo extensive proteolytic remodeling during development causing collagen degradation leading to a variety of life-threatening diseases such …
What is Iron-Hematoxylin Staining? This is a traditional staining technique commonly used for the detection of intestinal protozoans majorly because of its permanence and ability to demonstrate, observe, and quantify with high clarity protozoans nuclear structures. Iron hematoxylin was the stain used for most of the original morphological descriptions of intestinal protozoa found in humans. The iron hematoxylin staining method can stain …
What is Auramine- Rhodamine Staining? The evolution in staining methodologies has led to an era of modified staining techniques that are rapid, more versatile, and reliable in result interpretation. This is one of those techniques which was modified from the Acid Fast staining technique know as Ziehl-Neelsen Staining of Mycobacterium spp of bacteria. The major difference between these two techniques …
What is Papanicolaou Staining (Pap stain)? Papanicolaou stain is also known as the pap stain and the procedure of the stain is known as a pap smear. It is a polychromatic stain that uses multiple dyes to differentially stain various components of the cells. It is a histological and cytopathological staining technique used to differentiate cells in a smear preparation. …
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What is Ziehl-Neelsen staining? The Ziehl-Neelsen staining technique is a differential staining technique that was initially developed by Ziehl and modified later by Neelsen, hence the name Ziehl-Neelsen stain. Neelsen used carbol-fuschin from Ziehl’s experiment, with heat and added a decolorizing agent using acid-alcohol and a counterstain using methylene blue dye, thus developing the Ziehl-Neelsen Technique of staining. The use …
Read moreZiehl-Neelsen Staining- Principle and Procedure with Results