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Western blot analysis

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You ran your experiments on a gel and detected the proteins using a Western Blot (again remind yourself how do you make recombinant proteins, generate antibodies, and perform a Western). You results are demonstrated on this gel. The lanes are designated with the letter A-G. Vertical lines are partitions for the different set of experiments you did. Use this gel to answer the following questions:

1. Why are the bands for the cytosolic and the ER protein different? Compare lanes A and C.

2. From what you know about the signal hypothesis, why does the size of the protein in lanes A and B stay the same in vivo and in vitro? Why does the size of the protein in lanes C and D differ in vivo and in vitro?

3. When you added microsomes to your in vitro made ER protein, lane E, why is it the same size as the in vivo ER protein in lane C?

4. Why is lane F blank?

5. Why is there a band in lane G?

8-G) Lane G is confusing you a bit. You expect the protein to be the same size as lanes C and E. However this is obviously not the case. Why do you expect the size of the protein in lane G to be the same as lanes C and E? Could you think of a reason why the ER protein in lane G is much smaller than expected?

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Please see attachment for answers and modified image.

You ran your experiments on a gel and detected the proteins using a Western Blot (again remind yourself how do you make recombinant proteins, generate antibodies, and perform a Western). You results are demonstrated on this gel. The lanes are designated with the letter A-G. Vertical lines are partitions for the different set of experiments you did. Use this gel to answer the following questions:
Largest
Smallest

1. Why are the bands for the cytosolic and the ER protein different? Compare lanes A and C.
The simplest answer is that these are two different proteins. One is translated in the ER and the other the cytosplasm.

2. From what you know about the signal hypothesis, why does the size of the protein in lanes A and B stay the same in vivo and in vitro? ...

Solution Summary

Several paragraphs with web refrences answering questions involving western blot analysis.

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