If the only thing you had was a 8780 percentage methanol sol

If the only thing you had was a 87.80 percentage methanol solution and water and you wanted 270 ml of a 55 percentage methanol solution, how would you make it? You extract DNA from a sample and estimate it to be at a concentration of 20 mg/ml. You would like to load 20 ul of a 50 ng/ul in a well in a 1 percentage agarose gel. Write out a procedure that will allow you do to this. Starting from a 100 percentage solution (called Solution B). make dilutions (consider \"serially\" diluting) to prepare 100 ml of the following solutions. Write a step by step procedure to describe what you did. 30 percentage 5 percentage 0.1 percentage 0.001 percentage How many grams of sodium chloride would you dissolve in 500 ml to make a 0.075M solution? Do you add sodium chloride directly to a liter of water? Or, do you add water to the sodium chloride and bring up the volume to 1 liter? Why? How many mls of 6.0 N HCI are required to prepare 75 ml of 0.1 N HC1?

Solution

1) C1* V1 =C2 *V2

87.80 * V1 = 55 *270

V1 = 169.13 ml (ans)

Take 169.13 ml from 87.80% methanol and add 100.87 ml of water and this gives you270 ml of 55% methanol.

1) 1 mg/mL = 1000 ng/uL.

20 mg/ml = 20,000ng/ul

C1V1 =C2V2

20,000 *V1 = 20 *50

V1 = 0.05 ul. (ans)

Take 0.05 ul of DNA and add 19.95 ul of loading buffer.

2)

30% - Take 30 ml from 100% solution and add 70ml of water.

5%-Take 5 ml from 100% solution and add 95 ml of water.

0.1%-Take 0.1ml from 100% solution and add 99.9 ml of water.

0.001%-Take 0.001 ml from 100% and add 99.99 ml of water.

3)Molarity = weight * 1000 / molecular mass *Volume in ml

Molecular weight of NaCl = 58.44

0.075M = weight * 1000 / 58.44 * 500

weight = 2.19 g (ans)

5)We add water to sodium chloride and bring up the volume to 1 litre because adding salt to a liter of water will raise the volume above 1 litre as salt will mix with water to increase the volume.So, we can keep on adding water and check for the rise in volume and make up the volume till it becomes1 litre.

6) C1*V1 = C2*V2

6N* V1 = 0.1N* 75

So,V1 = 1.25 ml (ans)

We have to take 1,25 ml from 6.0N HCl.