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Old 03-24-2012
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Question Bchem

Question: After detailed evaluation of a 5 year old boy whose sclerae has the color of the blue sky, his physician determined that he has a mutation that affects expression of a certain gene coding for a protein. what is the best technique to establish if the gene is being translated in the culture medium of his body cells?

a PCR
b ELISA
c Sanger DNA Sequencing
d SouthWestern Blot
e Western blot
f Northen blot
h Southern blot
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Old 03-24-2012
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we are talking here about osteogenesis imperfecta.
type I collagen deficit


if the gene is being translated in the culture medium of his body cells?

-so we are talking here about translation, meaning that we got to deal with protein that is deficient... Meaning if we use western blot - we wont find anything.

So we got to go one step back and check the mRNA...
I guess we got to go with Northern Blot then (F)
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Old 03-24-2012
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Default DNA

DNA sequence analysis> pcr
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Quote:
Originally Posted by Rookie View Post
DNA sequence analysis> pcr
Except it's not asking about the sequence, as DocSikorski noted - so it would have to be RT-PCR or Northern blot for mRNA measurement, or Western blot for protein measurement. I think I'd actually go for Western on this one, based on the wording of the question ("translated" rather than "transcribed"). If, as DocSikorski said, no or little protein would show up against a control, then the test was diagnostically successful, right?
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i would go with nothern blot. It is asking only for the presence of RNA. It is not asking for measuring how much RNA (western blot)
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Quote:
Originally Posted by johnvega98 View Post
i would go with nothern blot. It is asking only for the presence of RNA. It is not asking for measuring how much RNA (western blot)
Southern finds DNA, Northern finds RNA, and Western finds a protein (and a Southwestern for DNA-protein interactions and a Northwestern for RNA-protein interactions, but I don't think you'll see those on the Step). A useful mnemonic is SNoW DRoP. Measuring how much RNA would be done by quantitative (real-time) PCR.
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Old 03-24-2012
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Quote:
Originally Posted by Mondoshawan View Post
Except it's not asking about the sequence, as DocSikorski noted - so it would have to be RT-PCR or Northern blot for mRNA measurement, or Western blot for protein measurement. I think I'd actually go for Western on this one, based on the wording of the question ("translated" rather than "transcribed"). If, as DocSikorski said, no or little protein would show up against a control, then the test was diagnostically successful, right?
I agree that it should be western blot
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Old 03-24-2012
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Correct Answer

Quote:
Originally Posted by Desos View Post
Question: After detailed evaluation of a 5 year old boy whose sclerae has the color of the blue sky, his physician determined that he has a mutation that affects expression of a certain gene coding for a protein. what is the best technique to establish if the gene is being translated in the culture medium of his body cells?

a PCR
b ELISA
c Sanger DNA Sequencing
d SouthWestern Blot
e Western blot
f Northen blot
h Southern blot

E = Western blot is the answer.
gene expression = transcription ( whose product is mRNA) and translation (whose product is Protein).

To establish if a gene is being successfully translated we need to identify it's product ---> Protein---> western blot technique
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Overthinking is as bad as under thinking...
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Quote:
Originally Posted by DocSikorski View Post
Overthinking is as bad as under thinking...
Hahaaha! That's totally true!
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E.....is the ans
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Mnemonic:
SNOW DROP

S D
N R

o o
W P

Southern = DNA
Northern = RNA
Western = Proteins
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Damn! jajajaj!! freaking genetics...
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Default Confusing!!

Thanks for the right ans Desos
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