Question

You also have the following stock solutions already made: 20% SDS, 5M NaCl, 500 mM EDTA, You have a 40% glycerol solution, and 10X TBE

1. Make 100 ml of 10% SDS, 1M NaCl

2. Make 100 ml of 10% glycerol solution

3. Make 40 ml of 0.5% agarose in 1X TBE solution

Must show calculations. I always get confused with % solutions.

Answer 1

1.

100 ml of 10% SDS,

how much of 20% solution need to be taken to make 100 ml of 10% solution

20% X = 10 % 100

X = 10 * 100/20

X = 50

that means we need to take 50 ml of 20% solution and add water to it to make the volume 100 ml.

1M NaCl f rom 5M NaCl

5 M X = 1M 100

X = 1* 100/5

X = 20

that means we need to take 20 ml of 5M solution and add water to it to make the volume 100 ml.

2. Make 100 ml of 10% glycerol solution

how much of 40% solution need to be taken to make 100 ml of 10% solution

40% X = 10 % 100

X = 10 * 100/40

X = 25

that means we need to take 25 ml of 40% solution and add water to it to make the volume 100 ml.

3. Make 40 ml of 0.5% agarose in 1X TBE solution

how much of 40% solution need to be taken to make 100 ml of 10% solution

1 X = 0.5 *40

X = 20

that means we need to take 20 ml