LB Agar (Lennox) Low-Salt 250 g – agar medium for bacteria

LB Agar (Lennox, Low-Salt) – agar medium for molecular biology

LB Agar (Lennox, Low-Salt Version) is a classic agar medium in the form of a dry powder, intended for the cultivation of bacteria, especially strains Escherichia coli used in molecular biology. The reduced sodium chloride content makes the medium particularly recommended for salt-sensitive experiments and for applications requiring a higher pH value. The product is available in 250g bottles, allowing for flexible adjustment of the prepared medium quantity to the current laboratory needs. For the inoculation of bacterial cultures, we recommend sterile petri dishes available from Googlab Scientific.

Composition, preparation and physicochemical parameters of the substrate

The LB Agar (Lennox, Low-Salt Version) formula is based on a proven formula, including 10 g of tryptone, 5 g of sodium chloride, 5 g of yeast extract, and 15 g of agar per liter of prepared medium, at a final pH of 7,5 ± 0,2 (25°C). To prepare the medium, weigh 35 g of dry powder, add distilled or deionized water to 1 liter, and then heat with stirring until the ingredients are completely dissolved and boiling. After pouring into appropriate containers, the medium is sterilized in an autoclave at 121°C for 20 minutes and, after cooling, poured onto Petri dishes, obtaining a uniform and clear culture surface.

Quality control, stability and storage conditions

Each batch of LB Agar (Lennox, Low-Salt Version) is quality controlled using reference strains Escherichia coli ATCC 25922, DH5α, and TOP10, incubated at 36 ±1°C for 12–18 hours. The acceptance criterion is a growth factor of PR ≥ 0,7, which confirms the medium's ability to ensure proper colonization and typical colony morphology. The product should be stored at 2–30°C, in the original, tightly closed packaging, protecting the powder from moisture. The shelf life is 36 months from the date of production. For safe inoculation and transfer of cultures, we also recommend sterile loops individually packed.