Question

I have some questions about SDS-page and BCA assay.

1. Why do ascorbic acid, iron, and tryptophan all increase the background in the BCA assay.

A. They oxidize the copper

B. They absorb in the same wavelength

C. They react with the bicinchoninic acid

D. They are reducing agents

2. Why does BCA require a standard curve?

A. the protein sequence influences color development

B. the development of color is time dependent

C. this controls for pipetting mistakes

D. this controls for dilution in the sample

3. If you have an interfering chelator in your sample, what should you do?

A. Give up, chelation is the worst

B. increase the amount of copper with more reagent A

C. increase the amount of copper with more reagent B

D. add an oxidizing reagent

4. A common theme between agarose and acrylamide gels is using different concentrations to separate different molecular weights. Which concentrations separate large species better?

A. high concentration agarose and high concentration acrylamide

B. high concentration agarose and low concentration acrylamide

C. low concentration agarose and high concentration acrylamide

D. low concentration agarose and low concentration acrylamide

5. What would happen if you skipped step 3 of the NextGel protocol?

A. It would be fine

B. The gel would leak out of the casting rig

C. The gel would never polymerize

D. There would not be a well to hold protein