The following dideoxy DNA sequencing gel is produced in a laborat...

Question

The following dideoxy DNA sequencing gel is produced in a laboratory.

What is the double-stranded DNA sequence of this molecule? Label the polarity of each strand.

Accepted Answer

Hi, everyone. Let's look through our next problem. It says gel electrophoresis is a technique for separating DNA R N A or protein mixtures by molecular size in the laboratory. Which of the following statements about the gel electrophoresis procedure is incorrect. So we're going to walk our way through the various answer. Choices. Remembering that we're looking for an incorrect statement about gel electrophoresis. So choice A says the gel has a positive charge at one end and a negative charge at the other. Well, this is a true statement that is how gel electrophoresis works. You put a charge across the gel and the molecules move if they're charged move in the direction of the opposite charge. So choice A being true is not our answer. Since we're looking for an incorrect statement. Choice B says because DNA has a negative charge, it will be drawn towards the gel's positive end. Well, this is true. That's what will happen. That's a correct statement and therefore not our answer. Then Choi says, since R N A has a positive charge, it will be drawn toward the gel's negative end. Well, this is false R N A like DNA has a negative charge. So it will migrate in the same direction as DNA and therefore choice C is our incorrect answer. Let's be thorough and look down at choice D. It says since proteins do not have a negative charge, they must first be treated with sodium, do decyl sulfate sulfate before being separated. Well, this is true. Proteins don't have a charge in general and won't run along down the gel. So they're given a charge by treating them with a detergent SDS. The SDS breaks down their structure into a linear form and then coats the entire molecule with a negative charge. So say uh gives the protein a negative charge. And that way, of course, they will migrate through an electrophoresis gel. But that's a correct statement and therefore not our answer. So again, the incorrect statement about gel electrophoresis is choice C since DNA or excuse me, since R N A has a positive charge, it will be drawn towards the gel's negative end. See you in the next video.

The following dideoxy DNA sequencing gel is produced in a laboratory. What is the double-stranded DNA sequence of this molecule? Label the polarity of each strand.

Key Concepts

Dideoxy DNA Sequencing

Polarity of DNA Strands

Gel Electrophoresis

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