Agar-Agar (Bacteriological Agar)

Agar-agar is a refined polymer driven from red algae. It is necessary for solidifying culture media in microbiology labs. Compared to gelatin, agar-agar is free of impurities and offers several advantages.
Agar-agar dissolves easily in boiling water but is insoluble in cold water. Significantly, it solidifies between 32 to 40°C, which is the ideal temperature range for bacterial growth and keeps its firmness at temperatures that are commonly used for bacterial cultivation. Agar-agar culture medium is extremely resistant to being broken down by enzymes released by a variety of microbes. This allows appropriate bacterial growth and ensures the integrity of the culture media.
Depending on the intended use, the agar-agar concentration in culture media can be changed.
To achieve the best solidification, bacterial culture media typically employ a concentration of 1–1.5%.
For motility experiments, a lower concentration of about 0.5% is utilized, enabling bacteria to travel through the gel more easily.
Certain anaerobic bacteria, which might be sensitive to a stricter environment, can be cultured at very low agar concentrations like 0.1%.
It’s crucial to remember that the acidity (pH) of the culture medium can have an impact on the gelling qualities of agar-agar. It may be essential to use a slightly larger concentration of agar (at least 2%) to achieve adequate solidification for pH values lower than 5.

Shelf life and storage
Store below 30 °C in a tightly closed container. Keep away for, heat and humidity. Under these conditions agar-agar has a shelf life of 5 years from the date of production.