sterilization n culture media

Sterilization

Rendering a medium or material free of all life forms

Autoclaving (Steam Sterilization)

The most common and effective method of sterilization, utilizing steam under pressure to eliminate microorganisms. The process typically involves heating the material to a temperature of 121°C (250°F) under 15-20 psi pressure for about 15-20 minutes. One of its key advantages is that it kills all forms of microorganisms, including tough bacterial spores, ensuring thorough sterilization.

Dry Heat Sterilization

Uses hot air, typically at temperatures ranging from 160°C to 180°C, to sterilize materials. The process involves heating the material in an oven for a set period, usually 1-2 hours. One of its main advantages is that it does not involve moisture, thus avoiding the risk of damaging heat-sensitive items.

Media

The nutrient preparations that are used for culturing microorganisms

Liquid or Broth Media

Type of culture media that does not contain any solidifying agents, allowing microorganisms to grow in a liquid form. A nutrient-rich liquid solution used for growing bacteria and other microorganisms, allowing easy observation of growth patterns.

Solid Media

Contains agar, which solidifies the media and provides a surface for the growth of microorganisms. A firm medium containing a higher concentration of agar (1.5–2%) to support the growth of microbial colonies for isolation and identification.

Semisolid Media

A low-agar concentration medium (0.3–0.5% agar) used to determine bacterial motility and oxygen requirements.

agar slant

If the medium is allowed to harden in a slanted position, the tube is designated an

agar butt-slant

if the tube is allowed to harden at an angle, the tube is designated an

agar deep tube

 if the tube is allowed to harden in an upright position, the tube is designated an

agar plate

if the agar is poured into a petri dish, the plate is designated an

broth tube

 A liquid medium is designated as a/an

culture medium

A liquid used to supply the nutritional requirements of microbes in growth and reproduction. It has to have the required nutrients, be permeable to oxygen or gases, and be at an ideal humidity level.

defined medium

All the ingredients are familiar to the researcher.

complex medium

Contains animal or plant tissue extracts such as beef extract or yeast autolysate, these extracts offer a broad range of nutrients in lipids, hydrolyzed protein (a form of nitrogen in the form of amino acids), carbon sources, vitamins, and cofactors