00:01
A simple chip sequence technique to decipher all of this, but not one of it option.
00:06
So what is the chip assay? so basically, chip assay is a short for chromatin immunoprecipitation, followed by dna sequencing.
00:16
So you can see from the name, chromatin means that you're looking at the dna, and ip is immunoprecipitation, followed by dna sequencing.
00:53
So i want to briefly introduce how this experiment was done, and you could see why one of the option is the correct answer.
01:01
So very first step, you use a cross -linker, usually fixed cell.
01:11
So fixative, kill the cell and use chemical bond to stabilize the interaction between the protein and the dna.
01:51
The second step, you're going to use enzyme to cut the dna, so we call chromatin fragmentation.
02:12
So the idea is that you have chromatin, and you cut them down into smaller fragments.
02:20
But at this time, because the cross -linker, dna and protein, they're still stay together.
02:28
The third step, we call this immunoprecipitation.
02:43
So we're going to use specialized antibodies.
02:52
The antibodies that you choose will actually recognize the protein that bound to the dna, because you can see that because the cross -linker, the protein are being bound to the dna fragments.
03:07
So these antibodies will actually recognize the proteins, and during the same time, the dna will be pulled down.
03:15
So you can see you have a red and black.
03:17
Red is the protein, and the black is going to be the dna.
03:26
And they stay as a complex.
03:28
They're being pulled down by the green antibody.
03:37
And then the next step, you obviously would want to do dna purification.
03:48
So basically, you separate the complex that has both protein and dna.
03:56
You want to purify this complex and separate the protein from the dna.
04:04
So you only want the dna.
04:06
You want to get rid of the protein.
04:07
Then you follow by dna sequencing analysis.
04:19
So after you finish all this step, you actually answer one question...