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Answering my own question after reading the 2018 Nature review article “mRNA vaccines — a new era in vaccinology” The resources and motivation engendered by the COVID-19 pandemic are a major factor in the development of the first mRNA vaccines approved by national governments. However, before the COVID-19 pandemic, there were recent advances in mRNA vaccine ...


17

I will try to answer the question in the title: how can we know the sites where DNA binding proteins bind? I'll explain two experimental methods to identify binding sites on DNA. DNase footprinting ChIP-seq (Chromatin Immuno-Precipitation with sequencing) DNase footprinting We can locate proteins bound to DNA by their ability to protect DNA from some ...


11

No, not all enzymes (or other proteins for that matter) can be obtained in functional form by recombinant expression with today's methods. As you suspect, problems arise when complex post-translational modifications are necessary to obtain the correct function. Direct modifications to peptide is one potential problem. Some of these can be resolved by ...


11

There are multiple challenges presented, and many of those are not limited to coronavirus vaccine. As mentioned above, it just takes time. Before a vaccine can be used in patients, clinical trials must be performed to validate the safety and efficiency of the vaccine candidate. A Clinical trial includes three phases, which again, just takes time. But to ...


10

Vaccine development is not as easy as just inject some inactivated virus as: Vaccine can have side effects such as inflammatory reactions. So for a good vaccine the side effects must be negligible or within a tolerable limit. Vaccine may not induce immune response. It may be ignored by the immune system as just some random debris. So a good vaccine must ...


7

ATryn is a human antithrombin produced in the milk of transgenic goats by GTC Biotherapeutics. It has FDA approval and I believe that it is available for prescription in the USA. Added later, after the emphasis of the question changed somewhat. Proteins produced in a mammalian system are more likely to have post-translational modifications that are much ...


7

Short answer All of your sources are correct as they are not mutually exclusive. PCR is used to isolate and amplify DNA to yield small quantities of pure target product. Gene cloning can subsequently be applied to scale the production of the fragment up. PCR thus can be part of the DNA cloning process. Background Cloning in general simply means duplicating....


7

GFP has a lot of advantages: The detection of the fluorescence works directly and doesn't need a lysis step or the uptake of a reagent. Fluorescence can be detected directly using a fluorescence or confokal microscope with the cells. This can be done while growing them on plates (works for bacteria and eukaryotic cell culture). You can sort labelled cells ...


7

Often artificial neurons are created with conventions that zero is "rest" and 1 is "threshold". The unit starts at 0, and when it reaches 1 it will send an input to all of its targets and be reset back to 0. This isn't exactly how real biological neurons work, but its a reasonable approximation in some contexts (and can do real world computations). Most of ...


6

The rationale for the choice of higher organisms as the producing source is based on costs and biological activity. Biological activity. In their active forms, various proteins have post-translational modifications (i.e. glycosylation) which are difficult to reproduce in bacteria. Alan's answer is already exhaustive. Costs. Mammalian cell lines are easier ...


6

This article gives an excellent review on yogurt manufacturing, but to summarize: -Raw milk goes through centrifugation to remove somatic cells and other solid impurities. -Thermalization is conducted at "60–69 °C for 20–30 s, aiming at the killing of many vegetative microorganisms and the partial inactivation of some enzymes." After this point, the milk ...


6

This is a very interesting question and I had not thought about it before. I am reiterating the background of your question. Background Cas9 cuts the both the strands of the target DNA at the same location thereby making a blunt end cut. Usually sticky ends and microhomologous ends lead to indels because of exonucleolytic clipping and addition of extra ...


6

This graph from the Broad's Opinionome blog (ugh) is somewhat more annotated: As noted elsewhere, the precipitous drop in 2007 is almost certainly due to maturing next-gen sequencing (NGS), in particular Illumina. Illumina acquired Solexa in 2007, which offered gigabase-level sequencing ability. In 2014, President of Illumina Francis de Souza essentially ...


5

Yes, bacteria will produce human (or any organism's) proteins if you introduce their genetic material but there are a few things to consider. First, the introns must be removed from the human genetic sequence. Bacteria do not have the machinery to splice out introns after transcription. This is typically done by using a viral protein to reverse transcribe ...


5

Biotechnology is a gigantic field. You should have a look at the wikipedia entry for biotechnology. Because of the size of the field "biotechnology", because the word biotechnology accept different definitions and because the word interesting is extremely arbitrary it is pretty much impossible to give a good answer to this question. I am using below ...


5

I think one of the orginal reasons for using biolistic on plant cells was that it seemed to be the only method which proved to be effective. This is due to some reasons: A wide range of highly successful methodes for prokaryotic cells (calcium chlorid method, electroporation) The plant cell has in comparison to animal cells a additional layer (= cell wall)...


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Edited after clarifications in question, Let's start with normal functions of both enzymes. Helicases separates DNA strands while polymerase synthesize DNA strands as shown in the following figure. (Image Source: Wikimedia Commons) Watch this animation, it will clear your doubts about function. However, RNA polymerase does have both activities. In cells, ...


5

I will assume that by "identical twin", you refer to "clones". Individuals who share the same genetics but of course do not necessarily share the same womb. I won't pay much attention in detail epigenetic modification nor in the length of telomeres. While it has never been done for ethical reasons, we would probably be quite able to make a clone of a human ...


4

Grossly, it does not matter what buffer you use. It is the pH that matters. For DNA electrophoresis EDTA is added in order to chelate divalent cations that serve as cofactors for nucleases. Tris is the base of the buffer and is used to set pH. Along with Tris one can use Boric acid, Acetic acid or phosphoric acid for adjusting the pH. The buffering range ...


4

The question which buffer for DNA is better is quite old. Both have their pros and cons and I list a few of them: TBE is a better conductor and is thus less prone for overheating the gel Borate is a powerful enzyme inhibitor, so if you want to apply enzymatic steps downstream, TAE is the better choice TAE gives a better resolution for large fragments TBE ...


4

I have had good experience using a lithium boric acid buffer from Faster Better Media. I use it for RNA gels, but it's advertised for DNA gels. I don't think it can do protein, but I've never tried it. I'm not an electrician, but higher conductivity may be the opposite of what you want. The lithium boric acid buffer claims to have less conductivity than a ...


4

NAD+ is important in this step, since it is co-factor for the glyceraldehyde-3-phosphate dehydrogenase (G3PDH), which acts as a acceptor for the hydrogen atom from the C1 (see below). If you look at the reaction, the aldehyde from the C1 is oxidized to a carboxylic acid which in a second step is turned into a phosphoester. To do so, a cysteine from the ...


4

According to this article, a single lacI gene copy gives rise to about 10 copies of lacI protein per cell, and we can conclude, therefore, that this is the amount required to keep a single lac operon repressed. The article also mentions the lacIQ mutation in the promoter of lacI that results in a ten-fold increase in the level of lacI protein. If a lac ...


4

There are already many great answers to your question, however I thought I put my comments in form of an answer. The standard for DNA agarose gel is TAE and for the protein, it depends on the size of the protein and the gel type used! Some times MOPS works best and sometimes Tris-acetate works best. It really depends on the gel used and also the protein and ...


4

Broadly speaking there are two classes of cell in an organism: Somatic cells These are by far the most numerous in your body, and are the differentiated cells including everything from retinal cells to liver cells to neurons. Stem cells and germ cells Stem cells reside in tissues and replenish the somatic cells as they are damaged or removed, or as the ...


4

Yeast can produce up to 16-17 v/v% ethanol without dying according to this article. Yeast is a primary industrial ethanol producer, it produces ethanol even under aerobic conditions, in contrast to bacteria that usually ferment sugar to ethanol under anaerobic conditions. Bacteria can also withstand up to several percent v/v concentration ethanol in their ...


4

It depends on the construction of the spectrophotometer, the wavelength of light you're detecting, and the sensitivity/accuracy that you're demanding of the result. In the past I have used spectrophotometers which were completely missing their sample lid, with no appreciable detriment to the result. Several things were in my favor, though. The light path ...


4

There is no general therapy for cancer - as there is no general cancer. Cancer is the umbrella term for a disease where you have body cells growing without control, leading eventually to death. But since there is a wide variety of cells in the body, there is also a very wide variety of different cancers. To treat these, surgery is often the first line of ...


4

One reason a Western blot is more specific than an ELISA - even one using the same set of antibodies - is background. Antibody-linked colorimetric reactions aren't completely on/off. There's always some background reaction. The antibodies are a little bit cross reactive, or non-specifically sticky, or the colorimetric coupling enzymes aren't completely ...


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