. SOC media is 2% tryptone, 0.5 % yeast extract, 10 mM NaCl (F. W. 58), 2.5 mM KCl (F. W. 74.5), 10 mM MgSO4 (F. W. 246.5), 10 mM MgCl2 (FW 203.3), 20 mM glucose (F. W. 180.16). Determine the amounts of each to make 500 ml of SOC.

10mL of tryptone, 2.5mL of yeast extract, 0.29g NaCl, 0.09g KCl, 1.23g MgSO₄, 1.02g MgCl₂ and 1.80g Glucose.

Explanation:

In 500mL = 0.500L of SOC, you must add:

Tryptone: 500mL × (2 / 100) = 10mL of tryptone

Yeast extract: 500mL × (0.5 / 100) = 2.5mL of yeast extract

NaCl = 0.500L × (0.010mol NaCl / 1L) × (58g / mol) = 0.29g NaCl

KCl = 0.500L × (0.0025mol KCl / 1L) × (74.5g / mol) = 0.09g KCl

MgSO₄ = 0.500L × (0.010mol MgSO₄ / 1L) × (246.5g / mol) = 1.23g MgSO₄

MgCl₂ = 0.500L × (0.010mol MgCl₂ / 1L) × (203.3g / mol) = 1.02g MgCl₂

Glucose = 0.500L × (0.020mol Glucose/ 1L) × (180.16g / mol) = 1.80g Glucose

it is the most commonly accepted one