Category: Stock solution

Poly-d-lysine promotes the adhesion and good growth of mammalian cells to the glass/plastic dishes. Here we describe a procedure to prepare a 1 mg/ml stock solution of Poly-d-lysine. The easiest way to prepare the solution is to buy a 5 mg poly-d-lysine (pack-size) and dissolve all of them in autoclaved sterile miliQ water without weighing it out. This stock solution can be used for coating glass coverslips to allow cells to grow adherently.

A 1M Sodium phosphate dibasic solution can be prepared by dissolving 141.96 g of Sodium phosphate dibasic (Na2HPO4, Molecular weight 141.96) in deionized water in a total volume of 1000 ml.

A 10 ml of 6X DNA loading dye can be prepared by dissolving and mixing 40 mg orange G, 25 mg xylene cyanol FF, 1.5 g Ficoll 400 and 0.1 ml of 1M Tris.Cl, pH 7.6 in sterile deionized or distilled water to a final volume of 10 ml.

SOB (Super Optimal Broth) medium is a nutrient-rich microbial growth medium, designed by Douglas Hanahan in 1983. SOB or its glucose-supplemented version SOC is often used during transformation of E. coli competent cells with plasmids (added in transformed cells after heat shock). It results in better survival and higher transformation efficiency as compared to regular LB medium. It contains 2% Bacto-tryptone, 0.5% Bacto-yeast extract, 0.05% Sodium chloride, 2.5 mM KCl, and 10 mM MgCl2. A 1000 ml SOB medium is prepared by dissolving 20 g bacto-tryptone, 5 g bacto-yeast extract, 0.5 g sodium chloride and 2.5 ml of 1M KCl in water to a final volume of 1000 ml. Medium is sterilized by autoclaving. MgCl2 (5 ml of 2M MgCl2) is added just before use.