Why is sterile water a good negative control for this PCR reaction?
827602
You're doing the PCR reaction to look for an amplification of a DNA segment.  When you run it out on a gel and look for the presence of bands of DNA, water will be your negative control because there is no DNA.  You want to do this to have something to compare your amplified sequence with; you also want to do this to make sure that bands in your amplified lanes are due to PCR and not to something DNA that was present in the water.
830851
it is the organism whose genetic sequence is completly studied.\nnot pathogenic so evenif escap from lab not causes hazardous effect.\npresent easily everywhere and isolation is also simple \ngrow on simple media\ngeneration time is less
64522
Why do you abuse this Answer system with your propoganda?  You didn't want an answer, you wanted to spew your pseudo-scientific garbage, and it looks like it failed.\n\nFluoridated water is safe and it's use is supported by REPUTABLE groups such as the ADA, AMA, WHO, CDC and hundreds of other scientifically SOUND organizations.  For a list of these please go to\n\nhttp://www.fluoridefacts.org/fluoride/flu_supp_org.asp\n\nMost groups that are against this tend to be fringe, self-serving groups who use scare tactics, innuendo, pseudo-science and other despicable techniques.  When faced with OVERWHELMING evidence from the scientific world I am sure you whip out the "conspiracy" BS too.\n\nThe vast majority of communities and people do not fall for this garbage and thus have a healthy fluoridated water system. \n\nYou should be ashamed of yourself for yourself for posted such poorly-documented pap.\n\nI am sure you are probably against the chlorination of water too.  Chlorine is poisonous too.....
994653
im a medical assistant at a drug testing facility. we have to tell people that the test in inconclusive or "non-negative" because we cant tell you that its positive. more than likely it will be if they sent it to the lab though. some medications, however, do show up (pain med, etc.). if it were diluted (too much water) it would have showed negative on a quick screen. (those only show neg or positive). e-mail me if you want to.
478310
As far as using for detection, its very vulnerable to showing false positives from non-specific binding.  In addition, because of the relatively low level of mRNA, it can only be used for fairly abundant messages.  It is somewhat difficult to separate non-specific from specific binding, but of course it can be done.  In addition, it only shows the presence of message-it does not tell about the level of protein translation.
790165
If you will settle for an RN I will give it a shot. China has had chronic problems with the purity of their water. They have dealt with this very nicely by boiling water and then drinking it hot. The same is true in many tea drinking cultures. They tend to have a much smaller rate of water born illness.
966826
check your stream water at above source soil runoff area,and compare periodic outfall testing in areas where there is an irregular out flow.you will discover a number of virulent bacteria changes with severe pollution.this is part of my study into the current worldwide MRSA infection cycles
852508
NaCl needs to be at the correct concentration, as it is needed to ensure that enzymes etc. work correctly.  It allows the cells to have the correct concentrations of sugars etc by influencing water entry by osmosis.\n\nA cell can take up a linear plasmid, but probably won't be able to propagate more copies if is isn't annealed, unless the correct DNA Ligase enzymes happen to be available in the cell.
917465
I always did the dephosphorylation simultaneously with the restriction. I used NEB restriction enzymes and shrimp alkaline phosphatase (SAP) from USB. As long as the total volume of enzymes as less than 10% of the reaction (to avoid too much glycerol in the mix) it worked fine.\n\nYou can heat inactivate XbaI. Also SAP is heat inactivated (though I haven't tried it). Check if CIP can be heat inactivated. If it can then probably you can get away with heat inactivation of the mix before using it for ligation. If however you have residual phosphatase activity then ligation will fail.\n\nIt looks like you have a medium or low copy number plasmid, but anyway since it is so big it sticks very well to the column.\nThe best choice would be to prepare lots of plasmid and afford a single purification step, just before doing the ligation.\nWhy don't you just use bigger culture volumes to get more plasmid? You could either do a midi or maxi prep, or use >1 mini-prep columns. \n\nI've been working with very low copy number plasmids so I know the problem. If you are cloning a PCR product I'd suggest that you first clone it in a simple high copy number vector like pBluescript, sequence it and then subclone it to your desired "problematic" vector. Otherwise you might get problems with the sequencing reaction-I've been there. If you are subcloning then OK.\n\nBy the way, the transformation efficiency for very big DNA fragments increases a lot if you add gyrase in the mix. I don't quite remember the citation (could be nucleic acids research) but I bet you can find it on Pubmed.
957716
Can this realy be true that there is an antifreeeze chemical for animal drinking water ?\nI doubt it. I am not a farmer, but I know that they simply keep the animal drinking vessels protected from the weather.\n\nI admit to not being an expert.
520769
Good news: You won't need to read a whole book to get even losts of details as well as the basics: google for a "polymerase chain reaction faq" on the web. Its less complicated than you think. \n\n\nWant to spend less time commuting ? Check out http://www.hallisystem.bravehost.com  \nWrite us.
858044
is intended to reduce the contaminations in products due to the amplification of unexpected primer binding sites. Two sets of primers are used in two successive PCR runs, the second set intended to amplify a secondary target within the first run product.
203956
Sterile technique and Universal precautions. You should not being doing this. A trained healthcare worker should. What are you doing this for?
1097639
Stenotrophomonas maltophilia has been well-documented as a nosocomial pathogen and has been implicated in cases of bacteremia, endocarditis, pneumonia and ocular infections. This organism was previously thought to cause disease only in immunocompromised or otherwise debilitated individuals, but recent studies show that S. maltophilia can behave as a true pathogen. There are many articles in the literature detailing hospital sites discovered to be contaminated with S. maltophilia. This organism is isolated most frequently from moist environments and has been found to colonize sources such as dialysis machines, nebulizers, shower heads, deionized water dispensers and ice machines. Patient risk factors for infection with this organism include prior antibiotic therapy, the presence of a central venous catheter or mechanical ventilator or underlying disease or malignancy.1\n\nStenotrophomonas maltophilia is resistant to many broad-spectrum antibiotics, especially those of the $-lactam and carbapenem classes. Trimethoprim/sulfamethoxazole is usually considered the drug of choice for treatment of S. maltophilia infections. Antimicrobial susceptibility testing is indicated for this organism with chloramphenicol and trimethoprim/sulfamethoxazole. This isolate of S. maltophilia is susceptible to both antibiotics
410493
I think it shouldnt matter with what you irrigate the foley's so long as you irrigate it often. The sole purpose of the irrigation is to prevent the clogging of the openings in the foley's at the end that is in the bladder. Therefore, what you use to irrigate shouldnt make much of a difference whether saline or sterile water. And it does indeed come right back out. Saline is sterile too, except that it has some electrolytes (ie, Sodium and Chloride) in it.
736773
There are too many things that might have gone wrong.\nYou are saying your template is a genomic DNA and then that it is plasmid ("if I shouldn't use a plasmid DNA") ? It can't be both, unless you mean you have a genomic library in a plasmid...\n\nplasmid templates are very good for PCR so that is definitely not the problem.(Unless the plasmid preparation is not good and you have e.g some ethanol or isopropanol or whatever in it.)\n\nIf you meant that you have a choice between genomic and plasmid template  go for the plasmid \nYou have to check again the design of your primers, the putative Tm, the size of the DNA so that you let elongation occur for enough time, etc...\n\nSome polymerases cannot cope with very long and difficult templates under usual conditions so you might have play with the conditions or change polymerase or use a polymerase mix.\n\nWe don't have enough info to be more specific. You just have to go through the design again carefully to see if there are any mistakes and then start changing conditions (Temperature, Mg concentration, annealing temperature varying with cycles, polymerase, etc)\n\nAlso if you designed the primers based on the cDNA but the template has introns, did you check that there are no introns disturbing the sequence which the primers should be annealing to?
163942
food water air reproduction