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7

To be honest, you really shouldn't be buying such things if you're not prepared to handle them properly. If you work with a proper lab, you will be inindated with vendors trying to sell you these and many others. But to answer your question, if you are looking to purchase many such items ATCC is an excellent resource. Not only will you have to meet ...


5

The minimum requirement for E. coli and other bacteria to grow and survive is called minimal medium. It's even defined at Merriam-Webster: a medium that contains only inorganic salts, a simple carbon source (as carbon dioxide or glucose), and water Water and glucose are pretty easy, but the source of salts may often change; regardless, you really need ...


2

Yes, but no. In other words, this quote is not probably not true in the ways you'd think. Bacteria can survive on practically nothing for long periods of time, but whether you call that life is subjective. Nitrogen is necessary for all the co-enzymes and proteins to sustain life. In order to get energy, if E coli. needs to metabolize nitrogen to waste at ...


2

There are three variables being shown here: The amount of time samples were stored in the freezer to allow $^{32}$P decay (x-axis), The length of time samples were allowed to grow in a nonradioactive environment before being frozen (points with different symbols), and The rate of $\beta$-galactosidase production when cells were thawed and grown in the ...


2

The traditional blue/white screening is set up so that blue colonies are considered positive for the insert, and white colonies are negative. The gene responsible is the lacZ gene, or beta-galactosidase. This enzyme converts a synthetic substrate, X-gal, into an insoluble blue compound. The pCR2.1 TOPO plasmid is a blue/white selection plasmid in which ...


2

In terms of naturally-occurring "genes" I think that the record is probably held by the attenuator peptides. In bacteria, the regulatory mechanism known as transcription attenuation involves the ribosomal biosynthesis of very short peptides. In the trp operon, where the phenomenon was first described by Yanofsky's group, the peptide, MKAIFVLKGWWRTS, ...


1

I did try another transformation: again with our electrocompetent cells Cells form other lab chemically competent cells I made The good thing is that on chemically competent cells there is no weir colonies, however efficiency of transformation was very low, but still, I think it is ok - will confirm it in next day if I really got the right insert. On ...


1

One textbook of microbiology suggests that the infectious dose of a specific strain of enterotoxigenic E. coli in adults would be $10^{8}$ cells. Keep in mind that infective dose will vary with species and strain, as well as the health, age and immune-status of the individual ingesting the bacteria. Children, elderly and ill people will generally be affected ...


1

The maximum temperature for E. coli to survive is dependent on the strain. E. coli from warm areas can easily survive 45 °C and more. The minimum number of E. coli to ingest in order to become ill is also dependent on the strain. Whether you become ill at all is also dependent on the strain. You harbor many billions of E. coli in your digestive tract without ...


1

That is a variable that you have the pleasure defining yourself. Just know that using a buffer will introduce other atoms that could affect the "living things". Conversely, if you don't use a buffer, it is likely that the pH of your "living things" will be easily altered by the metabolism of your living things (IMHO, this is worse). I don't know the details ...


1

According to this data sheet, the genotype of the strain RosettaTM(DE3)pLysS is F- ompT hsdS (r- m-) gal dcm (DE3) pLysSRARE (CamR). This strain carries certain tRNA genes on the same plasmid as the LysS gene, and these tRNAs boost expression from genes containing rare (in E. coli) codons. The plasmid encodes chloramphenicol resistance (CamR). If you have ...


1

Absolutely, Positive Selection You are looking for the bacteria which have the gene (probably a plasmid) you (or someone else for you) put into the bacteria. That gene lets them live in the presence of kanamycin, and any bacteria that don't have it, or that try to get rid of it, will die. Thus you can select for the bacteria you want by killing everything ...



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