Mueller Hinton Agar (MHA) – Composition, Principle, Uses and Preparation

Introduction The name Mueller Hinton agar(MHA) is derived from the names of co-developers, microbiologist John Howard Mueller and veterinary scientist Jane Hilton at Harvard University who first published the method in 1941. This Mueller Hinton agar (MHA) was a protein-free medium for isolating the pathogenic strains of Neisseria. Later in 1966, Muller Hinton agar (MHA) was adopted as the common … Read more

Sabouraud Dextrose Agar (SDA): Principle, Composition, Uses And Colony Morphology

Introduction Sabouraud agar or Sabouraud dextrose agar (SDA) is a selective medium for fungal culture and primarily used for the isolation of Dermatophytes, Yeasts and various other Pathogenic and Non- pathogenic fungi as well as it also supports the growth of Nocardia spp. and other filamentous bacteria. Moreover, the slightly acidic pH of this SDA medium inhibits the growth of … Read more

Tryptic Soy Agar (TSA):Principle, Composition, Preparation And Uses

Introduction Trypticase soy agar or tryptone soya agar (TSA) and Trypticase soy broth or tryptone soya broth (TSB) with agar are growth media for the culturing of bacteria. They are general-purpose, nonselective media providing enough nutrients to allow for a wide variety of microorganisms to grow. They are used for a wide range of applications, including culture storage, enumeration of cells (counting), isolation of pure cultures, or simply general culture. Principle … Read more

EMB Agar: Composition, Principle, Preparation, Uses And colony characteristics

Introduction Eosin-methylene blue (EMB) agar was initially formulated in 1916 by Holt-Harris and Teague, to visibly differentiate between the lactose fermenting and non-fermenting microorganisms through the use of eosin and methylene blue dyes. The medium also included sucrose to differentiate between coliforms that were able to ferment sucrose more rapidly than lactose and those that … Read more

Chocolate Agar: Principle, Composition, Preparation,Uses And Results Interpretation

Introduction Chocolate agar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria.It is a variant of the blood agar plate, containing red blood cells that have been lysed by slowly heating to 80°C.The name is itself derived from the fact that red blood cell (RBC) lysis gives the medium a chocolate-brown color.  Chocolate agar is used for growing fastidious respiratory … Read more

Nutrient Agar- Principle, Composition, Preparation, Results And Uses

Introduction Nutrient agar is a general purpose medium for the cultivation of organisms that are not demanding in their nutritional requirements e.g. organisms that can be isolated from air, water, dust etc.It is the most popular media that are generally available in all laboratories for enumeration of different bacteria and their maintenance.Nutrient is made up of: Principle … Read more

12 Difference Between Sigma Bond(σ) And Pi Bond(π)

There are two types of overlapping orbitals, that is, sigma (σ) and Pi (π). Both bonds are formed from the overlap of two orbitals, one on each atom. Sigma bonds occur when orbitals overlap in an end-to-end fashion, with the electron density concentrated between the nuclei of the bonding atoms also referred to as the … Read more

8 Difference Between Colloid And Suspension With Examples

What Is A Colloid? A colloid is a mixture with particles ranging between 1 and 1000 nanometers in diameter and still able to remain evenly distributed throughout the solution. In colloids the substances remain dispersed and do not settle to the bottom of the container. The colloid particles are generally larger than those in a … Read more