agarlevyt

Agarlevyt, commonly referred to in English as agar plates, are shallow, circular dishes that contain a solidified nutrient agar. They provide a flat surface for growing and observing microorganisms, such as bacteria and fungi, under controlled conditions. Agar plates are a standard tool in microbiology laboratories and education. These plates are often called Petri dishes.

Agar is a gelatinous polysaccharide derived from certain red algae that remains solid at room and body temperatures; when heated, it dissolves and becomes a liquid that can carry nutrients. A nutrient medium is added to the agar to support growth, and additional components may be included to create selective or differential conditions for distinguishing organisms.

The practice originated in the late 19th century. Fanny Hesse is credited with popularizing agar as a solidifying agent in microbiology, enabling stable medium for growth; the dishes themselves became widespread after Julius Petri and others used them in bacteriology laboratories.

Typical uses include isolation of pure colonies, observation of colony morphology, and qualitative testing in research, clinical, and educational settings. Plates can be pre-prepared commercially or prepared in laboratories; they are often used in conjunction with sterile technique to minimize contamination.

Handling requires adherence to biosafety practices, including appropriate containment, labeling, and disposal. Used plates are typically disposed of or sterilized before disposal in accordance with local regulations. Agar plates are a fundamental, widely used tool for studying microbial growth and diversity.