Question

Prepare the buffer. In this lab we store our buffer at a concentration 20 times the concentration used in the experiment. Thus we call it 20xLB. Before we can use it, it needs to be diluted to a 1x concentration. If we needed 20 mL of the media, we would take 1 mL of the 20xLB buffer and diluted it with 19 mL of Dl water. To make enough buffer for this experiment, we need 50 mL for the gel and 300 mL for the buffer chamber. 1. How much 20xLB buffer do we need for one gel and buffer chamber? 2. How much Dl water would we need to add to dilute it to the final volume? ml

Answer 1

Answers : 17.5 ml and 332.5 ml respectively

There is a simple formula that can be used :

N1V1 = N2V2

where,

N1 = Concentration of the stock buffer

V1 = Volume to e taken from the stock

N2 = Concentration of the final experimental buffer

V2 = Volume (required) of final experimental buffer

here,

N1 = 20

N2 = 1

V1 = Needs to be identified

V2 = 350 ml

thus,

20 * V1 = 1 * 350

V1 = 350/20 = 17.5 ml

Thus, we require 17.5 ml of buffer for one gel and buffer chamber.

DI water to be added to dilute the buffer = (350-17.5) ml = 332.5 ml