Kary Mullis talked out about the huge flaws in HIV leading to AIDS theory, such mistakes that’s huge percentage of the population still aren’t aware of , crazy 😜
Something that made me scratch my head: The synthesis of DNA goes from 5' to 3'. But this is on the _synthesised_ strand, not the _template_ strand. So at 1:33 he chalks in the nucleotides on the end labelled 3', but remember DNA is anti parallel and the new 5' end will line up with the old 3' end.
MrGoatflakes If you look at the figure on the board you will see two DNA strands, one in blue that is left to right running in the 5' to 3' direction and one in orange that is left to right running in the 3' to 5' direction. These are two complementary strands of the original DNA molecule that will be amplified.Each of these strands will serve as a template for the synthesis on a new strand. In each case, a primer will bind by base paring to the template strand and new nucleotides will be added to the free 3' hydroxyl of each primer. Each newly synthesized strand will be made in the 5' to 3' direction.
I know I'm 8 years late to the conversation, but when you use heat to denature the DNA strand, are we assuming that helicases cannot be used? I'm just used to helicases causing the DNA strand to split rather than heat.
Well it's not the PCR method but dideoxy termination sequencing, nonetheless it's very interesting and the teacher is so attractive that I feel quite in love with him.
While PCR is exponential (a pair of different primers), Sanger Sequencing is linear and made each strand (a single primer) at a time... They are not the same, they share the fact that they are DNA synthesis based techniques...
What about bacterial DNA? Since it is circular, one could expect that at each PCR cycle, elongation of the new strands should stop only after the completion of the full circle. How can then we achieve isolation and replication of a particular segment? Must we first break the DNA at some point so as to transform it from circular into a linear double strand?
I know that restriction endonucleases are used to break up DNA. They have the property of snipping wherever a certain very short combination of bases appear, and which sequence they cut at depends on the particular nuclease. Many cut in such a way as to leave an overhang or "sticky end", where the double strand has a short single strand overhang. I don't know if you can use the predictable sequence at the start of the cut is long enough to make a useful primer, but if not I'm guessing what you could do is make something that complimented the sticky end, along with extra, random but known bases, amplify that once and THEN use the compliment of that as your primer for the main PCR reaction.
For a second I thought he said "and their useless" at the end LOL. What he was talking about at the end sounded a lot like the Sanger method - is that the same thing or something else in this case?
Hello. I don't understand one thing (so far): How do we know that this particular primer is going to "bond" with our target sequence? We need to know, on first hand, the sequence we desire to amplify. Right? So, for that, we need to know the genome. Thank you.
Você pode conhecer de antemão uma pequena região da sequência, até mesmo pelo uso de analogias em organismos modelo. Um primer costuma ter de 16 a 28 (tipicamente 20) nucleotídeos e os fragmentos que você amplifica com PCR podem ir de menos de uma centena (ex: ALU, microssatélites) até milhares de pares de base de DNA. Uma forma tradicional de revelar-se "de novo" (do zero) é clonar fragmentos via DNA recombinante. Hoje utiliza-se o Sequenciamento de DNA de Nova Geração (NGS).
Attention all professors: writing sh**out on a chalkboard and explaining it is a great way to teach! Reading some lame powerpoint for 70 minutes or so? no so great. BTW- Great explanation, clear and to the point! Thanks
