HW 9 - SP2 - Affinity Chromatography to Purify an Antibody - 5 pts
We need to purify an antibody which is to used as an affinity adsorbent in the production of a synthetic vaccine. The feed contains 1.63 g antibody and 0.45 g of a protein of similar molecular weight. We use gel permeation chromatography to obtain the following results.
Time(h), Antibody Concentration y1, Impurity Concentration y2
6.42 , 82 , ~ 0
7.00 , 63 , 0.14
7.60 , 28 , 43 (peak)
a.) Use these reults to plot the antibody and impurity yields as functions of time on the same graph.
b.) Plot the purity as a fuction of time.
Time(h), Antibody Concentration y1, Impurity Concentration y2
6.42 , 82 , ~ 0
7.00 , 63 , 0.14
7.60 , 28 , 43 (peak)
a.) Use these reults to plot the antibody and impurity yields as functions of time on the same graph.
b.) Plot the purity as a fuction of time.
posted by Dr. B at 8:52 AM
9 Comments:
7.6 is not the "to" for y1, right?
so how can we find the yield for antibody?
Dr. Phil:
That is the correct approach. But I did make a typo/omission in this problem statement. The antibody {t,y} is a peak at 6.42 h and y0 = 82 units.
Yes, t0 = 7.6 h and y0 = 43 units for the impurity.
t0 = 6.42 h and y0 = 82 units for the antibody.
Anon:
t0 = 7.6 h and y0 = 43 units for the impurity.
t0 = 6.42 h and y0 = 82 units for the antibody.
Again the yield is defined from t' = 0 in the lab, but from t' = -infinity in the Gaussian peak and yield equations.
In making the plots in Excel, you may run into some quirks with Excel's error function.
Erf(-#) => error #NUM
Erf(-#) = - Erf(#)
One way around this is to use the ABS and SIGN functions in Excel.
Try using: SIGN(#) * Erf( ABS(#) ) instead of erf(#) when you are calculating the yield. SIGN(#) gives -1 when #<0, +1 when #>0 and 0 when #=0.
Erf(30) => error #NUM, this should not be an error ! Erf(30) = 1.
how to calculate the purity? what is the total volume of the feed?
For the purity, should we use the mass given to find the respective mole fractions? Or is the yo referring to the yo given?
Purity is defined in the PPT from Mon, slide 3.
I don't understand why you want to know the total volume of the feed. You can make your plot go from V = 0 to any final V that makes your graphs look complete.
jack daniels:
The y0 is the y0 that you "determined" from the given data.
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