Ok, I'll try and answer your questions in a way that's easy to understand without much background knowledge.

>how does one extra extract DNA from cells
For most labs, we have kits that allow us to burst open the cell and nucleus, and then filter out the DNA from other cellular components with specialised membranes.

>sequence the DNA genome
Lots of ways here. For whole genomes, is basically a lot of random sequencing all over the genome, followed by finding overlapping regions and assembling it into a whole genome.

> build custom genes
I'm not entirely sure what you mean by this. If you mean causing mutant genes, this can be done by adding chemicals which disrupt the gene replication, adding errors. If you're going for a specific mutation, then can be designed in with PCR (explained later).

>put the genes back in.
Enzymes are used to cut the DNA unequally, leading to short single strands being present. If the gene you want to insert has been cut by the same enzyme, it will attach to the single strands, and insert.

>Polymerase Chain Reaction
Aka PCR. It's an incredibly useful method for amplifying genes. By using two short single stranded DNA chains as primers, you can highlight the region to amplify.
Temperature is cycled to achieve the following: DNA is seperated into to single strands, primers bind to the complimentary site, and DNA polymerase uses the primer to start replicating the DNA. This is cycled multiple times to produce lots of the gene of interest.

>>8079533
I forgot one part of your question.

> put it back in the cell
By treating the cell with chemicals affecting the cells channels, you can induce a stress state with heat that causes the cell to uptake any DNA from the external area.

>>8079533
>Lots of ways here. For whole genomes, is basically a lot of random sequencing all over the genome, followed by finding overlapping regions and assembling it into a whole genome.
Doesn't explain how actual sequencing is done.

>I'm not entirely sure what you mean by this
He probably means how to synthesize a gene in vitro or something.
>Enzymes are used to cut the DNA unequally, leading to short single strands being present. If the gene you want to insert has been cut by the same enzyme, it will attach to the single strands, and insert.
Wat. You use restriction enzymes for putting genes into plasmids.
For genomic integration you need more than this.
>DNA is seperated into to single strands, primers bind to the complimentary site
You need to lower the temperature after denaturation to allow primer annealing.

Seems like you could use a bit more background knowledge yourself brot ;)

>>8079533
>extracting DNA

Sometimes they use very fine microscopic needles to suck out the nucleus.

>Sequencing

I did a lab or two on this. A simple and primitive way is to take a sample of DNA and conduct a "gel-electrophoresis" thing where it separates segments of DNA according to size. There's a specific type of enzyme or protein that can bind to the DNA in this process that caps off the DNA at every base pair so it can be read properly (base pairs are A, T, C, G, which make up DNA).

>Reinserting genes

Plasmids are sometimes used, as are viruses. Usually, as mentioned, they will use restriction enzymes to cut the DNA at certain points to get exactly what they want.


>PCR

makes a lot of fucking genes

>>8079671
>that sequencing explanation
Wat.
The most common (at least I think it used to be) sequencing method is Sanger sequencing.
Basically, you use fluorescent dideoxy nucleotides during PCR coupled with gel electrophoresis to determine the sequence.

>>8079663
1. I am not going to explain the god knows how many sequencing methods are out there, especially with the advent of NGS.

2. Synthesize a gene out of what? You don't just splash some reagents together and POOF a gene appears.

3.try ligate any gene without using restriction enzymes. See how far you get. Fair point about the genomic integration though.

4.thats correct. However I am trying to keep it not too detailed.

Sounds like you could pull your head out of your ass more brot ;)

>>8079685
>3.try ligate any gene without using restriction enzymes. See how far you get. Fair point about the genomic integration though.
https://tulane.edu/sse/tgmouse/pronuclear.cfm
(;

You seem to be wondering more about the technical aspects of biotechnology than microbiology and genetic, op.

>how does one extract DNA from cells?
when I did research we used kits to do it. The specific chemicals used differ from kit to kit but many use stuff like a silica membrane for the DNA to adhere to in a small tube.

>sequence the DNA genome
sequencing shorter strands of DNA usually uses SBS/pyrosequencing (with flourescent labels for the dNTPs). Sequencing an entire genome requires other methods such as primer walking and multiple sequence cycles (polymerases are not as efficient in the lab vs in the body, obviously)

>build custom genes
using PCR, we created unique plasmids in the lab and used them to create mutants of B. unamae. CRISPR is a relatively new method which uses enzymes to edit targeted genes, but I have never done it so I don't know too much about it myself

>splice those genes into specific parts of a genome
depends on an organism. For bacteria, since it's a single cell, you can have a plasmid (aforementioned in the previous paragraph) which the adjacent genes surrounding the region of the genes you want to "splice" in. Recombination will occur then you can test to see if the genes are "spliced" in via PCR and then confirming on a gel. With multicellular organisms that mate, you extract the embryo then do this (please note I have only worked with bacteria/viruses, I'm not very sure with multicellular organisms)

>insert back into a cell
usually it's done directly in the cell.

PCR is praised because of all the applications it brings and how easy/convenient it is, you can amplify DNA from even a single strand of template. This opens up doors to many, many different uses such as in criminal investigation.

t. third year undergrad microbio student in uni, take everything I said with a grain of salt. If I said something that's not right please let me know.

>>8080255
I should also mention for building "custom" genes or "splicing" genes in a specific part of a genome, there are various different methods, I just posted some I did in research