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You could be measuring outside the dynamic range of the assay (you can only add so much / so little BSA to a certain amount of reagent). You could be outside the linear range of your spectrophotometer, usually under 1 is fine, although some old/crappy ones might not even be reliable over 0.5. If you're fast you're measuring your different concentrations ...


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If you look at the DNA sequence in the patent, you will see that it does not start with ATG and does not end with a stop codon. The disclosed sequence has some additional bases in it, therefore the discrepancy in protein and DNA length. Those additional bases almost always occur in cDNA, e.g. because of polyadenylation, Kozak sequences, etc.


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If you're expressing the gene in E. coli, then you're almost certain to be using a plasmid or other ectopic gene vector. There are a wide variety of plasmids available, with many different promoters. With a commercial plasmid, you're not adding in the promoter sequence, but the gene sequence. You pick the promoter you want and then clone your gene sequence ...


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It depends on how much time elapsed between adding the concentrated antibodies to the diluting solution and adding the diluted antibodies to the slide. If it was just a couple of seconds, then I can abolutely see there being a difference. Even if it was longer - say 30-90 seconds, even - there potentially could be antibody gradients in the solution without ...


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That is a very bad test case. The problem is that the sequences are too short and involve a long repetition. This means that the default gap penalties and the gap-length penalties are not applicable. They are designed to work with longer sequences, where the penalty of inserting a gap can be offset by an increase in matches. In any case you can get bad ...


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Your guess is made without knowing protein substitution probabilities. Optimality of alignment in BLAST is a metrics of the scoring function. The scoring function depends on the word size (length of the seed that initiates an alignment), rewards and penalties for matches and mismatches - gap cost and substitution matrix. In general, BLAST uses BLOSSUM and ...


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Needleman-Wunsch does an end-to-end (global) alignment (BLAST uses Smith-Waterman). Needle from the EMBOSS toolkit performs Needleman-Wunsch alignment. It will report the highest scoring alignment. I am not sure which alignment it reports when there are two of them with equal scores (I don't think it is random). I just tried your case: replaced B with W as ...


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Your question is quite vague so I can only give you a vague answer saying what I would expect given only the information of your question. The vagueness mainly comes from the huge amount of functional sequences in the genome, particularly also in enzyme-coding genes, each being more or less conserved. You say I am surprised that there is no ...


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There are several mechanisms by which the expression of a gene can be completely turned off. Certain network architectures can ensure foolproof repression (for e.g. by using multiple repressors parallely or additional epigenetic silencing mechanisms). Bistable switches can also ensure robustness of expression in a way that small fluctuations in the ...


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Your understanding of DNA is correct. DNA is a heteropolymer of monomers called nucleotides and each nucleotide is made up of a sugar (deoxyribose), phosphate and a "base" (A, T, G, C). As you already know, DNA is organized as a double helix with the Watson-Crick pairing rules. A chromosome contains a single DNA double helix. Many organisms have multiple ...


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You ask initially about the “sense” and “antisense” strands of DNA. These terms are explained in the Wikipedia reference entitled ‘Sense strand’. This states what you appear to be already aware of, that: “The sense strand is the strand of DNA that has the same sequence as the mRNA, which takes the antisense strand as its template during transcription…” ...


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I would add this as a comment to your question but do not have enough reputation. A simple look at Wikipedia (which is a very good source for general questions like these) would have provided you with an answer. I just did this to see how long it would take if I did not know the answer. It was about 20-30 seconds. Protein synthesis: Transcription In ...


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It is common in biology to use a virus to deliver new genetic information to a cell. Such a virus is called a viral vector. Retroviruses can be used to enable the viral DNA to be incorporated into the cell's genome. Usually viral genes are removed, making the virus unable to replicate once the cell is infected 1. Using viral vectors in vivo to "correct" ...


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As I commented, a bolus is a single (often large) dose of a drug or compound given (released) all at once. Please read the very next sentence after the one you quoted: For example, the lethal and edema toxins of Bacillus anthracis disseminate within the host bloodstream and act upon both immune and nonimmune cells. This gives an example of a pathogen ...


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Usually, toxicity is given in the units of mass of the substance per unit mass of body mass of the organism that will kill 50% of the organisms in a species if those organisms ingest the toxin at that dose (e.g. mg/kg, ng/kg). This measurement is called the median lethal dose, and is often abbreviated as LD50. In your table, they only provide the mass of ...


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Decreasing the number of essential amino acids is frequently used as a selection marker during molecular biology experiments: An organism (usually yeast) that cannot synthesize a certain amino acid is first grown in the presence of said amino acid in the media. Then it is transfected with a gene of interest together with the gene that enables it to ...


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In a word: mutation. If you step back and think about it, multicellular organisms are really, really complex systems. Different cells have to do different kinds of things and interact with each other, they form organized tissues and organs and so on. That much is obvious. For all of this to work in concert, cells have to grow and divide (to replace dying ...


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I would rather use the synthetic analogon IPTG for induction of genes behind a lac promoter, as they are not getting degraded (or at least much slower than lactose) and thus give a much stronger induction signal. You will need to test the optimal IPTG concentration, but as a starting point I would use and endconcentration of 1mM. If this is not optimal (to ...


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What should be the correct reason for bilayer arrangement? I'll answer your second question first, but there is an almost identical question on this site already: Why do cells have a bilayer? There is water on the extracellular and intracellular side of the membrane. What's actually happening at a molecular dynamics level is the self-association of the ...


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You are correct in saying that Crick, in his Wobble Hypothesis, proposed that “the base on the third position of the codon and that on the anticodon need not be complementary”, but the “need not be” in your statement is a paraphrase of the “some” in Crick’s original statement: “It is suggested that while the standard base pairs may be used rather ...



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