The period when most of the bacteria are competent is

Most bacteria are in the period of receptive fetus, which is the quiescent stage, because the bacteria are less active and grow slowly during this period.

Most bacteria are in a state of feeling in the spirit world, a period that has never been seen in a time that is about to happen.

It indicates that the bacteria have grown to the middle and early logarithmic growth phase (i.e., the cell population is in the prime of life).Competent cell cultures can transform each microgram of supercoiled DNA at a frequency of 5x10 colonies.

Most bacteria are in a competent state of mind in humans or animals, which is the incubation period.

The period of being competent is when the object expires for food, and bacteria will multiply, so I hope you should be aware. All bacteria are produced when they are not clean.

The period when most germs are competent is when I think it should be the period of transmission, so at this time we should keep our distance from other people, and preferably in an enclosed space by ourselves.

Most bacteria are in a competent period and are already not earning, not not quite normal anymore, because the bacteria are acting in the body to get in. The length of time that the environment particularly allows is probably that it will become inflamed on the cabinet. So at this time you are.

Most of the bacteria are in the uh is competent period, yes, this is generally cold weather, cold weather, this bacteria are easy to multiply very quickly.

Most bacteria, of course, are in that period of feeling, and it is very good to be able to feel a thing by itself.

Most bacteria are in a competent period, so it can let other plasmids into their cells, so that some foreign genes can be added to the bacteria.

Bacteria Chunyu just said that his period was well at the beginning, that is, the primary stage.

Well, it's that he's not in danger, but it's there, it's a hidden danger.

When the bacteria were in a competent state, this is a medical problem, I don't know, I'm sorry.

It is said that his bacteria are also in the period of damage to its infection, we should be the earliest period, I think this is also necessary to check.

You're right, most bacteria are less susceptible to infection when they are competent.

What is the feeling state of most bacteria, you can look it up in the book, go to the biology book and go to the Western Wall.

Most bacteria are in the receptive phase, and most bacteria only appear when they are sick.

Most bacteria are in a competent period, that is, to get it right, most bacteria need to figure out, which bacteria are they?

Most bacteria are in a competent period, and this is of course the most active.

The period when most bacteria are competent is the most unclear.

What is the internship where most bacteria are competent? The period when most bacteria are in a competent state is winter.

Competent cells.

When preparation, there are requirements for the concentration of cell cells.

Plasmid. Quality and concentration of DNA:

The plasmid DNA used for transformation should be primarily.

Supercoiling. state, conversion rate with.

The concentration of exogenous DNA is proportional to a certain range, but when too much amount or volume of exogenous DNA is added, the conversion rate decreases. In general, the volume of the DNA solution should not exceed 5% of the volume of competent cells, and 1 ng of cccDNA will saturate 50 μL of competent cells. For recombinant molecules with plasmids as carriers, the conversion efficiency of large molecular weights is low, and experiments have proved that those with large molecular weights are greater than 30 kb.

Recombinant plasmids. It will be difficult to convert. In addition, recombinant DNA

The configuration of the molecule.

The conversion rate of the circular recombinant plasmid is 10 100 times higher than that of the linear recombinant plasmid with the same molecular weight, so most of the recombinant DNA is cyclical.

Double helix. Molecule.

2) Quality of competent cells: buried.

used. cacl2

and other reagents must be of the highest purity, prepared with the purest water, and preferably stored in 4 aliquots

3) The growth state and density of the cells.

Preferably from -70 or -20 glycerol.

The stored cultures are directly transferred to the bacterial solution used to prepare competent cells. Do not use culture solutions that have been transferred multiple times and stored in 4. The cell growth density is preferably around 5 107 cells per milliliter of culture medium.

That is, the application of logarithmic phase or logarithmic prophase bacteria, can be determined by the determination of the culture medium.

OD600 control. For TG1 strains, when the OD600 was 0 5, the cell density was about 5 107 ml. (It should be noted that the relationship between OD600 values and cell number varies with strain).

Too much or too little density can reduce conversion rates.

b) Effects in competent cell transformation:

The entire procedure should be carried out under sterile conditions, using utensils such as:

Centrifuge tubes. Pipette gun.

The first class should preferably be new and autoclaved. All reagents should be sterilized, and care should be taken to prevent them from being sterilized by other reagents

DNases. or contamination by miscellaneous DNA, otherwise it will affect the transformation efficiency or the transfer of miscellaneous DNA. The entire procedure needs to be performed on ice and cannot be left from the ice bath, otherwise the cell conversion rate will be reduced.

Suspicion file one. Material.

DH5 strains: R, M, Amp; PBS plasmid DNA: Buy or lab made, Eppendorf tubes.

Two. Equipment: Constant temperature shaker, electric constant temperature celery incubator, desktop high-speed centrifuge, sterile workbench, cryogenic refrigerator, constant temperature water bath, ice making machine, spectrophotometer, micro pipette.

Three. Reagents Solid and liquid media.

Mother liquor 3LB solid medium containing AMP: The prepared LB solid medium is autoclaved and cooled to about 60, the sample storage solution is added to make the final concentration of 50ug ml, shake well and plate.

4.Maconkey Agar: take 52g of MacConkey Agar, add 1000ml of distilled water, boil until completely dissolved, autoclave, wait to cool to about 60 Add sample storage solution to make the final concentration of 50ug ml, and then shake well and coat the plate.

CaCl2 solution: weigh CaCl2 (anhydrous, analytically pure), dissolve in 50ml of redistilled water, set to 100ml, and autoclave.