Comments
This is another rich medium for the growth of bacteria. The original recipe of LB medium does not contain NaOH. The medium is not very highly buffered, and adjustment of the pH to 7 will not prevent that the pH drops when a culture grows near to saturation. Lennox-Medium differs from Miller-Medium just by the quantity of sodium chloride. The packaging sizes differ in terms of the amount: you can choose between packages in liter (L) or gram (g) and kilogram (kg), respectively. Liter packs dissolved in the corresponding volume will give the correct concentration. When using the gram and kilogram packs, aliquots of the powder have to be dissolved. To prepare one liter of LB-Medium according to Lennox, 20 g of powder are dissolved.Directions to prepare 1 liter medium/agar: Dissolve the powder in 900 ml of water; adjust pH to 7.0 with 5 N NaOH (approx. 0.2 ml), fill to 1000 ml and autoclave. Antibiotics and nutritional supplements should be added only after the solution has cooled to 50°C or below, sine many of them are heat-sensitive.
Literature
(1) Ausubel, F.A., Brent, R., Kingston, R.E., Moore, D.D., Seidman, J.G., Smith, J.A. & Struhl, K. (eds.) (1995) Current Protocols in Molecular Biology. Page 1.1.2 (Suppl. 59) Greene Publishing & Wiley-Interscience, New York.
