how the principles of gel electrophosis allow for the seperation of DNA fragments?
111490
Ahh...thats easy...After putting the DNA in the holes, and turning on the electric field, DNAs move to the (+) pole because they have a (-) charge....Small DNAs move faster and they separate so the result is seen on the gel...
1098660
Your question isn't easy to read, but i think i understand it enough. There is one mole of 1kbp DNA strand with an EcoR1 restriction site in the middle. The amount of 5'ends produced when you addd EcoR1 to the DNA will be double because you will be effectively cutting the DNA in half. I hope this is what you were asking
281036
It is not possible to divide a cell without replicating its DNA. This is how it works: DNA replicates during interphase. So now we have two copies of the same genetic material. These two copies then split apart into two cells in mitosis and cytokinesis. The result is two identical cells with the same genetic material as the parent cell.\n\ndid it help, or make it more confusing?
81840
Think of a gel as a web of fibers, either polyacylamide or acrose.  This web creates a maze for the molecules to run through with the smallest molecules advancing faster than the larger molecules.\n\nDNA, in particular, creates a problem.  The molecules are very long and fiber-like.  They have a tendency to get hung up on the fibers of the gel.  Pulse field electrophoresis provides a solution.\n\nIn pulse field electophoresis, the voltage difference across the gel is reversed repeatedly to prevent the problem of the molecules getting stuck on the fibers of the gel.  Initially, the positive charge is placed at the bottom of the gel.  As the DNA moves to the positive end, some of the molecules will get hung up.  So, at some point in time, the field is reversed so the positive charge is at the top of the gel.  The DNA molecules then move to the top of the gel.  Any hung up molecules are then freed.  Then the field is reversed again, so the molecules can continue their journey to the bottom of the gel.  The process is repeated several time throughout a gel run.
825088
The lipid parts have a cation binding site to bind with the negative charges of the DNA.  The final complex is called a liposome.  \n\nIt then carries the DNA into cell and into the nucleus.  You still have to use a bunch of reagents in the process.  This is just from my research background.  The specifics are long.  You can email me for them
822273
Hi. DNA is a very simple structure that has a very complicated role. Free radicals (oxygen ions, for instance) can damage the DNA in a cell. It would require removal of the cell's DNA to do what you propose. May be better to neutralize free radicals in the first place.
790485
I've answered a similar question in the past\n\nhttp://answers.yahoo.com/question/index;_ylt=ApDo1VHr18AJSQm6WOxC_8Dsy6IX?qid=20061028024332AAKbYkD\n\nor copy pasting...\n\n"The more bulky the molecule the harder it is for it to move through the gel pores and thus the slower it will run.\n\nThe order in a gel would be\ncircular nicked (so there is no supercoiling)\nlinear\nsupercoiled\n\nObviously from this order supercoiled is the fastest running, though sometimes it can run at the same height as linear.\n\nThe migration of linear DNA is the one representative of the actual size."
569746
It goes away during the beginning so the DNA can get out, then it reforms after the cell splits into two separate cells.
1138370
That DNA of different sizes will migrate through a gel at different speeds.\n\nDNA is charged, so applying an electric current will cause the DNA to migrate down the gel, the smaller the piece, the faster it goes.  So you can separete pieces of different lengths, or estimate the size of your band by comparing to a standard ladder.
342631
Before a cell can divide, it must duplicate all its DNA. In eukaryotes, this occurs during S phase of the cell cycle. \n\nA portion of the double helix is unwound by a helicase. \nA molecule of a DNA polymerase binds to one strand of the DNA and begins moving along it in the 3' to 5' direction, using it as a template for assembling a leading strand of nucleotides and reforming a double helix. In eukaryotes, this molecule is called DNA polymerase delta (δ). \nBecause DNA synthesis can only occur 5' to 3', a molecule of a second type of DNA polymerase (epsilon, ε, in eukaryotes) binds to the other template strand as the double helix opens. This molecule must synthesize discontinuous segments of polynucleotides (called Okazaki fragments). Another enzyme, DNA ligase I then stitches these together into the lagging strand. \n\nWhen the replication process is complete, two DNA molecules — identical to each other and identical to the original — have been produced. Each strand of the original molecule has \nremained intact as it served as the template for the synthesis of \na complementary strand.\nThis mode of replication is described as semi-conservative: one-half of each new molecule of DNA is old; one-half new
1187682
seperates the stuff it needs to keep in (DNA, nucleolus, microtubules) and the stuff it needs to keep out, out (like other organelles, etc).  It may also have a function in the earlier stages of meiosis (pre-prophase)
722061
polyacrylamide Gel Electrophoresis
860270
Hi - here are some ideas without seeing your actual data.  First - the system was too hot during transfer to  the membrane - be sure you aren't running it at too high  a voltage.   Second, not an issue with the  blot,  but with  the gel  - was it expired?  not fully polymerized? were the  wells free of debris when loading  samples?   sometimes with highly concentrated samples, especially cell lysates,  this  can  happen  because  of  viscosity  in t he  sample  (from  DNA for example). good  luck.
752091
Go read this article from the Whitehead Institute for Biomedical Research \nhttp://www.wi.mit.edu/news/archives/1996/pk_0828.html
468872
DNA is composed predominantly of a phospho-ribose sugar backbone.  Due to the high phosphate content (which is negatively charged), the DNA molecule has an overall negative charged and migrates towards the positive electrode in a gel system (such as agarose or polyacrylamide).  \n\nThe positive electrode is referred to as the "anode" and is commonly the Red electrode in these systems - DNA "runs to Red".
661254
electroporation just opens big holes (pores) on the cell membrane.  Once the holes are there, you can introduce the dna by just floating it in the same solution.  Electroporation has about a 70% integration percentage, while other less high tech methods have about a 20 to 30% only.  Your highest percentage will be with a virus or plasmids, but that takes far more manufacturing than just having the dna and send it in through electroporation.\nCheers.
203875
Usually described as about 2 meters for all of the dna in one human cell.  This actually consists of many separate strands of dna.