34 lines
1.6 KiB
Markdown
34 lines
1.6 KiB
Markdown
---
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date: 2024-08-01
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tags:
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- biokemi
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- provfråga
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- plasmid
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---
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**Uppgift**
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A gene of interest was amplified and verified using the blue/white screening method. The
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plasmids from two bacterial colonies, one blue colony and one white colony, were purified. Then
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restriction enzyme digestion was performed, and the samples were run on a gel as follows: white
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uncut, white cut, blue uncut, blue cut (see figure below). After imaging the gel, we can conclude
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that while there is plasmid DNA in all samples, the white sample was probably mixed with the
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blue sample. Explain what finding in the gel indicates the white sample was probably mixed with
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the blue sample by referring to the size/number of bands. Account for the other source of error
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for this outcome besides pipette tip contamination from sample to sample. (4p) (Max 200 words)
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OBS! This question needs to be answered in English.
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**Answer**
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the findings in the gel that indicate that the samples were mixed are the lines in
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the white uncut sample. It has two visible bands, with one lining up quite nicely
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with the blue uncut bands in size. If the plasmid is uncut, than there shouldn't
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be two distinct bands because the sample only consists of an uncut product. The
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white uncut should also have a larger amount of base pairs than the blue
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uncut because we have transformed a gene of interest into it, but they seem to
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have the same amount.
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a source of error for this outcome could be that the colony picked for the white
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cut may have been close to a blue colony - causing a small amount of the blue
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colony to be accidentaly picked.
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Ord: 131
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Totalpoäng: 4 |