00:01
So which of the following is not a component of a pcr reaction? so let's talk about the typical pcr reaction component.
00:13
You obviously will need a dna template.
00:17
So this is the sequence that you want to amplify by pcr.
00:23
The next component that you must have obviously is the individual deoxynucleotide.
00:29
So these are basically the dna nucleotide, single nucleotides that are used to make new dna strands.
00:40
Other than that, you'll need tac polymerase.
00:45
The polymerase is the enzyme that actually adds the deoxynucleotide to the growing chain of dna.
00:55
And of course you have primers.
00:56
The primers will bind to certain regions of dna template.
00:59
This is the starting point of dna synthesis.
01:03
Tac polymerase does not know where to begin unless you already have primers.
01:09
So for pcr reaction, usually there are two primers and the region in between the primers will be amplified.
01:19
All right.
01:19
So now a lot of time the pcr reaction must happen in a salt buffer.
01:26
So this offers the optimal ion concentration and also it has magnesium in it.
01:36
Magnesium is a necessary component or cofactor for tac polymerase.
01:43
So without the magnesium ion, tac polymerase doesn't work.
01:47
So as you can see, these are all necessary components of the pcr reaction.
01:52
The only one that is not part of the standard pcr reaction is going to be c, calcium ion.
02:00
Calcium is not in a regular or standard pcr reaction list.
02:07
So that's the first question.
02:09
So let's look at the second question, which is a blank fling question.
02:13
So before a region of dna can be amplified, one must identify and determine.
02:20
So this is a blank.
02:22
So the first blank is the sequence of a piece of dna.
02:32
So to do pcr reaction, you will have to know the sequence, especially the flanking region of the dna that you want to amplify, because you need to design primer according to this sequence of a piece of dna.
02:54
And so where is the sequence that you have to know? so it must be upstream and downstream of the region of interest...