Question

A stock protein sample that has a concentration of 250.0mg/ml. You need to dilute this sample to 20.0 mg/ml in buffer. The final volume of the diluted solution is 5.0ml. how much of the stock protein solution and buffer are required to achieve this? Answer with appropriate sig figs.

Answer 1

you want 5ml of 20mg/ml in buffer.
you are diluting the solution 250/20 times, or 12.5 times. So you need one part original protein sample, 11.5 parts buffer.

What is each part? 1 part=5.0ml/12.5=4ml
11.5 parts= 46ml