Capsule Stain Microbiology
It is secreted by the cell itself and adheres to the cell wall. Capsule stain is a type of differential stain which involves the use of two stains.
Use the other slide to drag the ink-cell mixture into.
Capsule stain microbiology. The water-soluble capsule of some bacterial cells is often difficult to see by standard simple staining procedures or after the Gram stain. The bacterial cells will be stained purple. Capsule Stain procedure Place a single drop of India ink on a clean microscope slide adjacent to the frosted edge.
India ink method uses two types of stain ie. When this secretion remains loose and un-demarcated it is called a slime layer and when it is organized into a sharply defined structure it is called as Capsule. The purpose of the capsule stain is to reveal the presence of the bacterial capsule.
Methods of Capsule Staining India ink Method. Place the end of another clean microscope slide at an angle. Capsule Stain The capsule stain employs an acidic stain and a basic stain to detect capsule production.
Using sterile technique add a loopful of bacterial culture to slide smearing it in the dye. Using a flamed loop and sterile technique remove some Klebsiella pneumoniae from culture tube or plate and mix it into. The copper sulfate washes the purple primary stain out of the capsular material without removing the stain bound to the cell wall.
In the capsule staining method copper sulfate is used as a decolorizing agent rather than water. Primary stain and the counterstain. Abstract Bacterial capsules are composed of high-molecular-weight polysaccharides andor polypeptides and are associated with virulence and biofilm formation.
Congo Red is easier to. This method makes the use of two reagents namely crystal violet as a primary stain 20 of CuSO4. In capsule staining a smear of bacteria is made at the center of a slide.
All of the principal pathogens which cause pneumonia and meningitis including Streptococcus pneumoniae Haemophilus influenzae Neisseria meningitidis Klebsiella pneumoniae Escherichia coli and group B streptococci have polysaccharide capsules on their surface. Here its worth noting that for most part capsules are non-ionic. Procedure of Capsule Staining Place a small drop of a negative stain India Ink Congo Red Nigrosin or Eosin on the slide.
To distinguish capsular material from the bacterial cell The capsule stain is a differential stain used to detect cells A gelatinous outer layer that is secreted by the cell and the 7 Terms. Young fresh cultures wont have developed capsules yet. A capsule is a gelatinous layer which lies immediately exterior to the cell wall and is often referred to as a slime layer.
This unit describes two methods of capsule staining. The capsule if present will appear clear against the dark background. Since the presence of a capsule is directly related to a microbes virulence its ability to cause disease the ability to determine whether cells in a sample have capsules is an important diagnostic tool.
This is usually composed of polysaccharide polypeptide or both. In this procedure we use a combination of a simple stain and a negative stain. October 8 2020 Sushil Humagain Bacteriology Microbiology 0 Capsule staining is a differential technique commonly used in light microscopy.
Capsule Staining Certain bacteria and yeasts have a protective outer structure called a capsule. Capsules are formed by organisms such as Klebsiella pneumoniae. The ability to produce a capsule is an inherited property of the organism but the capsule is not an absolutely essential cellular component.
A basic stain Crystal violet and an acidic stain. Negative stains will stain neither the capsule nor the cell resulting in a puffier-looking cell but one in which the cell and capsule cant be distinguished from one another. Most capsules are composed of polysaccharides but some are composed of polypeptides.
If you are staining an unknown organism be sure your culture is several days old. Capsule staining methods were developed to visualize capsules and yield consistent and reliable results. Background capsule bacterium TIP.
It is not heat-fixed as the cell shrinkage caused by heating may create a clear zone around the cell which may be mistaken as capsule. Unfortunately capsules do not stain well with crystal violet methylene blue or other simple stains. INTRODUCTION TO CAPSULE STAINING TECHNIQUE A capsule in bacteria is the result of amorphous viscid secretion released by the bacteria.
As a result acidic and basic stains will often fail to adhere on to them. Many bacteria secrete a slimy viscous covering called a capsule or glycocalyx. Capsule also known as K antigen is a major virulence factor of bacteria eg.
