CharonY

If you include shotgun-sequences there are far more than a few hundred. Most are not well annotated, though. But to your primary question, the prices have been going down rapidly in recent times. However, you have to consider that you do not only need the naked DNA, but you have to build libraries first. Anyhow one of the cheapest ways for bacterial genomes atm is the use of a 454 sequencing system, and it will work fairly well if you already got genomes of somewhat related bacteria. The costs will be around 20-25k$ if you do it yourself. Personell costs will add to it if you pay someone else to do it though. I assume that it will almost double the price, but I am not sure. I could find that out, but I assume that the question was academic in nature? Forgot to add, the sequencing itself (assuming that DNA of sufficient quality and quantity is already present) will take around a week with the 454. Time for assembly varies, of course

Yup, you got it right. Regardless of background, the important thing is to know which information is missing and where to get it. That's why I described the cell wall setup rather than saying "outside", which probably wouldn't have helped much in the long run. Now regarding penicillin and bacterial cell walls. Unlike the plasma membrane the cell wall is basically porous. As such it is for the most part not a barrier for instance for antibiotics. Be advised, however, that many Gram-positive bacteria (those that possess a cell wall system as described above, Gram-negative bacterial cell walls are setup differently) often a additional layers on top of the cell wall (e.g. mycolic acids and surface layer proteins) that might act as barriers.

Of course no one ever directly counted the cells. However adult humans consist of roughly 10 e12 cells. In the intestinal tract alone (where the highest amount of bacteria are found) there are around 10e14 bacteria. The composition of bacteria varies greatly according the given habitat, of course.

This is very easy. Imagine the setup of a the bacterium. Staphylococcus is Gram-positive. So you got the plasma membrane then you got a multi-layered cell wall consisting of peptidogylcans. So the function of the protein in question is involved in the cross-linking of the cell wall. So where, logically, does the active part of the protein has to be located?

The thing you may have missed is that the endonuclease creates sticky ends. So you digest the plasmid and the vector carrying the insert with SexAI individually. Then you mix the digested fragments. Due to the overhangs the insert can then attach to the digested plasmid and then get ligated.

Well your OP is a bit vague in what you want to do. So I just assume you want to make a simple experiment involving bacteria (that is the cheapest way). So it splits up into the following areas: Cell incubation and harvesting: you got to grow your cells. An incubator that actually holds the temp is not that cheap, roughly you got to invest at least 2000$. I am not including running costs of the media. If you want to make it on your own, you need a way to sterilize it. Otherwise buy premade media (kinda expensive, though). You need at least a microcentrifuge at various points. Uncooled ones start at around 3000$. Make recombinate DNA: cheapest way is to amplify a gene and clone it into a vector. For this you need a thermo cycler (~5000), an electrophoresis system (to check the DNA) consisting of a chamber and a power unit (~1000, cheaper if you build the units yourself). Introduce DNA into the cell: one the easiest way for you would be to buy competent cells. They are kind of expensive, but then you do not need an electroporation system or a cooling centrifuge (~7000$). You have to decide whether you prefer high initial or running costs. Finally you need a pipetting system and all the consumables (including chemicals and kits). In real labs the latter is often the costliest part.

You overlook the second important function of red blood cells. What other gas plays a role?

If integrated into the hosts genome it is not longer directly infectious. Only the complete virus particle (RNA + Capsule) is. A chunk of genomic DNA even if containing viral sequences cannot infect you.

Well, check the properties of the respective amino acids (into what category do they fall, respectively) in each organism. This should give you the right idea.

The guys identifying the less specific restriction by EcoRI (the Boyer's lab, I think) termed the activity EcoRI* to distinguish it from normal enzyme activity. The asterisk was then later on translated to "star".

Annotation means assigning information to a stretch of DNA. Basically you only have the naked base pairs. Then you make ORF predictions (that is, identifying regions that might get transcribed), with further analyses you can then call it a gene and assign a function to it. The whole process, especially the latter part is called annotation.

Curation of gene sets of genomes loosely refers to overseeing, annotating or manipulating gene data (often manually). This may include: - fine annotation of genes - filtering of genes according to certain parameters - construction and manipulation of gene models and so on.

To be more precise LB is for the most part (10g) tryptone (tryptically digested casein) , half of it yeast extract (5g) and depending on formulation (Miller or Lennox) 5-10g NaCl. For agar slants you require to add 1.5 % agar into it. This is a so-called complex medium and not only E. coli, but also copious other bacteria and fungi will grow on it. Generally it is not a good idea to grow bacteria under these conditions, if you cannot work sterile, as you cannot exclude that you might grow pathogens. An alternative might be the use of minimal media (containing only the essential salts and vitamins) to limit unwanted growth, but this is far more laborious. In theory tupperware might work though. You have to thoroughly sterilize everything beforehand, and then use a large enough tupperware box. You only pour in a little bit if the medium into the dish so that you will enclose enough air if you seal it. If the box is large enough, there should be sufficent oxygen to grow some colonies. Still, I'd always advice to be careful working with bacteria.

DrDNA, if there were conductive and non-conductive nanotubes for reasonable prices (with a special focus on the price) I might actually be interested. Another problem with nanodots as labels, btw, is their ability to blink. Not few measurements screwed up due to this. In a way the phrase: "nanotechnology is the future" has a lot of truth to it. The majority is still is still in the area of basic research, meaning that only few of the current ideas will eventually hold water- in the future.

A problem with nanotechnology is that it has become a bit of a buzzword, similar to "systems biology". It lacks a coherent, stringent definition. In principle you can put so many things from different disciplines into that word so that it might essentially become (almost) meaningless (it just has to be small). In the few posts in this thread we have already seen examples of it. I could add plenty from the direction of biology and biochemistry. In scientific terms it is something under which you submit your grant application, if funds are available and you work with smallish things...

Let's put it like this, the species is the strongest possible taxonomic unit. However its universality is being questioned (especially in prokaryotes, though even in higher eukaryotes it is not that straight-forward anymore). As such it is unlikely that races are anything more than arbitrary distinctions with hardly any biological basis.

Actually the evolution of sex is far more complicated (mot to mention heavily discussed since the 80s). It has been stated that sexual reproduction would increase the fixation of beneficial mutations at different loci. On the other hand, there is little data that heritable variance of fitness is really increased by sex. In fact, recombination can lead to the breakup of favourable sets of genes and thus reduce fitness. Also, if all things being equal, an asexually reproducing female will have double the production rate than that of a sexual female. The latter is also the reason why tri-sexual mating is rather unlikely as it would increase the cost of sex even more. Overall to date there is no definite explanation why there is sex at all. More specifically it is unclear how sex initially evolved (as on its onset the additional costs should lead to its demise pretty fast) and how it is maintained. It is clear that it is a successful mode of reproduction, although quite a large number of animals and plants (not to mention prokaryotes) still reproduce asexually. A more molecular explanation stems from the similarity of the DNA repair and the recombination machinery. More recent evidence indicate that chromosomal recombination is in fact a by-product of DNA repair. As such ecological selection might play a smaller role than initially thought and chromosome maintenance selection might play an additional role. Spinning this further it has been proposed that sex originated from a form of genomic parasitism. Transposons, for instance rely on sexual recombination to spread and it has been hypothesized that sex is established to foster the spread of these mobile elements (selfish genes in action).

Actually I was quite dumbfolded when I first read that. Why should it be advantageous to die before getting cancer (dead is dead, you cannot reproduce either way). But after re-reading I am pretty sure that this statement is based on a simple misunderstanding (or maybe misformulating?). Essentially cell division (and cell aging) are strictly regulated (best known element is probably telomere shortening). In theory deregulated cells can divide longer and faster, though, which can reduce effects of aging. The downside is that this increases the risk of cancer. So essentially there is a trade-off between cell aging and cancer, with the mechanisms selected to maximize the overall reproduction efficiency of the organism. Death by aging occurs almost by definition later, when (as lucaspa pointed out) reproductive abilities were reduced (or absent), anyway. This is an example of the so-called antagonistic pleiotropy theory of aging, which states that pleiotropic alleles (in this case those controlling cell division) that increase survival/reproduction in early life but decrease the same at late life, can accumulate in a population because the selective advantages of the former outweigh the cost of the latter. Under the so-called mutation accumulation theory it is assumed that deleterious alleles can accumulate if their negative effects are confined to the old age when the selective forces are lower. If the first case was true that any change in genes involved in senescence will have an impact on early-life fitness (for example, increased cancer risk), whereas according to the second theory it would not be the case. As usual the in reality probably both effects play a role.

Essentially I agree with what the others said. Information gained by forced speed reading also tends not to stick into long-term memory. Reading regularly will increase your reading speed anyway. I heard that it might be worth to avoid regressions (involuntarily rescanning already read words), though. This on the other hand can also be achieved by regular reading.

Ouch. overlooked that part.

Hedges and Nowell, Science. 1995 Jul 7;269(5220):41-5 Further examples and elaborations were also given in these books: Biology at work – rethinking sexual equality by Kingsley R. Browne. Rutgers University press. New Brunswick ISBN 0813530539 Divided Labours – an evolutionary view of women at work by Kingsley R. Browne. Weidenfeld & Nicolson London ISBN 0297841408 Darwinism Today series. Series Editors Helena Cronin and Oliver Curry. A contrasting view was put forth in the commentary of the Nature magazine by Barres (Vol 442, 13, July 1996) Actually I read them mainly out of interest, but it is kinda helpful if you are a yourself in a position in which you at least have some influence about giving jobs to someone in science. As a male one can find oneself quite quickly in the sexist corner if one is not careful enough (hence I need good data, or at least literature).

Actually I would rephrase it to:"it could eventually lead to an adult human." While we would like to perceive biological processes in a fixed, mechanistic way, what is actually happening depends on a lot of things strangely not going wrong.

I stumbled over a rather old one: Wendy et al 1991

Nope, there is no evolution tree (using quotation marks doesn't make it better). At the very best one can envision an evolutionary bush with all extant species on the same level. Based on this the rest of the argument is pretty much moot. I am no expert in this field, but what I remember is an ongoing argument about the nature of consciousness (whether it exists, can be localized to brain areas, is an emergent property or not, the molecular basis and so on), and even more so on trackable markers for the same (e.g. language, tool usage and so forth). Based on this there cannot be any clear-cut, absolute separation of humans from other animals with at least a certain degree of brain complexity.Most argument discussing the "specialness" of human consciousness is based on similar arguments put forth by thedarshade: human cognitive abilities (and by extension, humans in general) are special, hence they are different. General consensus is that mammals apparently have the highest potential for higher levels of consciousness, although there are studies indicating that many birds also display behavior usually associated with cognitive behaviour (e.g. see Butler AB, Cotterill RM. 2006 Mammalian and avian neuroanatomy and the question of consciousness in birds. Biol.Bullet.). In the end however, there is not easy measurable marker (or even definition) that can be used to quantify consciousness.

The qiaex kit contains a protocol for the extraction of DNA from polyacrylamide gels, if I recall correctly. Essentially you need to let the DNA diffuse out of the gel matrix with a certain buffer, then you have separate the gel from the DNA solution (as it cannot be dissolved like agarose gels). The recovery rate was lower though. You can also do it without columns, but then you need to clean up e.g. by ethanol precipitation. Should work, but the recovery is likely to be even lower.