Question

S., Finish this protetn purification table: (4 pts) volume 10 ml 12.5 Fraction 56.3 25.36 Homogenate DEAB Gel filtration Was this a 'good purification? Evaluate the purification results. (2 pts) 6.

Biochemistry Question:

I'm having trouble understanding how to calculate % yield with the given information (Volume & Concentration), I don't necessarily need the answers, but I'd like to know how to calculate them. Additionally, while I'm asking this, how could one evaluate those results to determine if the purification was 'good' or not?

Thank you

Answer 1

% yield represents how much of the enzyme desired was actually recovered. So to calculate it you must have the data of total activity units obtained in each step of purification.

The data of protein obtained in each step doesn t represent the quantity of the protein you are purifying only.Is a mixture of proteins, so you cannot used it for calculate the yield.

Activity units data is specific for the protein you are purificating. (1 activity unit = 1 micromole of product obtained per 1 minute / ml)

Fomula

: total activity units( en each step) / intial activity units x 100

So with the given information you cannot calculate % yield

A good purification process take account in 2 parameters high final protein recovery with high % yield ( total activity units)

Final protein obtained could have good yield but it can be recovery in a low concentration or viceversa .In both cases, you have to improve the purification process .

From the data of the table you can see that the % final of protein recovery was 7.2%.

( from 563 mg protein in homogenate, you obtained 40.6 mg of total protein in the final step)

With this data, you cannot conclude if the purification was good, you need activity units data.