You identify a previously unidentified plant species and decide to study its genetics. You establish true breeding strains for leaf shape (longer than wide vs equal length and width) and flower color (white vs. yellow). When you perform a dihybrid cross with these strains, you find that your results are very different than those predicted by a 9:3:3:1 ratio. You calculate a chi square and get a p value of less than 0.0001. Which of the following statements is most accurate based on this observation?

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#Question id: 18846

#Unit 13. Methods in Biology

For an application where you require a sample of your target protein at high purity, what would be a good purification strategy? Assume that your starting point is E. coli cells in which the target protein fused to an affinity tag has been over-expressed.

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#Question id: 18847

#Unit 13. Methods in Biology

You know that the protein you want to purify from a natural source forms a multimer with multiple sub-units giving a molecular weight in solution much bigger than visualised denatured on SDS-PAGE. There is only a small amount of the target protein in the total protein sample. Which of the following is an appropriate purification strategy?

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#Question id: 18848

#Unit 13. Methods in Biology

You find that your protein sample loses activity during storage. What can you do about this?

TLS Online TPP Program

#Question id: 18849

#Unit 13. Methods in Biology

Which of these techniques is often considered a suitable "polishing" step in a protein purification strategy?

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#Question id: 18850

#Unit 13. Methods in Biology

Which of these chromatography types are suitable as a "capture" step in the purification of non-tagged proteins?

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#Question id: 18851

#Unit 13. Methods in Biology

Nickel-NTA (Ni-NTA) chromatography is a popular affinity chromatography method for the purification of histidine-tagged proteins. However, SDS-PAGE of the eluted protein can show bands in addition to your target protein. How might you improve this purification step?