I. You are making 500 ml of Luria Bertani (LB) broth, and the ingredients are li
ID: 1045806 • Letter: I
Question
I. You are making 500 ml of Luria Bertani (LB) broth, and the ingredients are listed as followed. Determine how many grams of each ingredient you will need. After you make the LB broth, you take 300 ml out of the 500 ml to make another special type of media. This special type of media is made by adding additional 1% Fetal Bovine Serum (FBS) and 3% histidine (His) to the original LB broth. Y% LB Broth (500 ml) 0.5% yeast extract 0.75 % NaCl 1.0% tryptone Grams needed LB (300 ml) + FBS + HisGrams needed 1% FBS 3% HisExplanation / Answer
making 500 ml lb broth solution :
stock solution are : 20% magnesium sulphate & 10% ammonium phosphate solution
final volume of making solution is 150 ml .
1) 3% magnesium sulphate = (150*3%)/20% = ( 150*0.03) /0.20= 22.5 ml ( remember 3% = 3/100 = 0.03)
hence for making 150 ml solution we need to pipette out 22.5 ml of solution from 20% magnesim sulphate solution to make 3% of its final concentration in 150 ml solution.
2) 0.05% ammonium phosphate : (150*0.05%)/10% = (150*0.0005)/0.10 = 0.75 ml
hence for making 150 ml solution we need to pipette out 0.75 ml of 10% ammonium phosphate solution.
3) 1.5% sodium chloride : 150*1.5% = (150*1.5)/100 = 2.25 grams
water required : final volume 150 ml
magnesium phosphate 20% = 22.5 ml
ammonium phosphate 10% = 0.75 ml
both solution volume = 22.5+0.75 = 23.25 ml
hence water required = 150-23.25 = 126.75 ml
for 150 ml solution add 22.5 ml 20% magnesium sulphate sol. + 0.75 ml ammonium phosphate 10% sol. & 126.75 ml water but in water we have to add 2.25 grams of sodium chloride
LB broth 500 ml grames needed 0.5% yeast extract = 500*0.5/100 =2.5 grams 0.75% NaCl = 500*0.75/100 =3.75 grams 1% tryptone = 500*1/100 =5 grams