Thermalless Magnetic cycling PCR There is a document about using micronewtons of force rather than warm cool cycles to do PCR cycling. There is an online image of a Neodyium magnet moving lipid bubbles around at a water alcohol blend. Thus just use a magnet to wiggle lipidised PCR reagents to create the micronewtons of force used to do PCR (Of course you could use other things besides lipids to create diamagnetic difference, like bismuth or cyclic compounds.)
Very similar technology creates a Genechip (gene detection array) with adjustable contrast as well as specificity. Just put the DNA probes on c-c-c-c-c-c-c lipidlike longifiers(possibly of variable length with different amino acids), then use magnetism to electronically wiggle the longifiers more to vary reaction time or attachment strength.
The tremendously brave might suggest Magnetic PCR adjacent to a gene assay chip to create an ultrasensitive electronically adjustable DNA or RNA detector, its even possible that as minronewtons of force make it work, it could automatically rinse, wiggle apart from the previous sample, then do a fresh sample.-- beanangel, Feb 04 2012 water oil system that does things with diamagnetism http://www.otherpower.com/diamagh2o.html [beanangel, Feb 04 2012] PCR with micronewtons of force http://www.freshpat...ptan20060019274.php20060019274 Thus, a polymerase reaction cycle can be initiated by increasing tension applied to a DNA template to above about 65 pN to denature the DNA. A step corresponding to the annealing of primers can be effected by slowly decreasing tension on the DNA template to below about 50 pN to allow primers to anneal to the template. Tension in the DNA template can then be adjusted within about 0 to about 30 pN during extension of the primer via enzymatic polymerization in order to control the progress, rate and/or accuracy of the replication. [beanangel, Feb 04 2012] sub-sub-micron magnetic beads http://www.turbobeads.com/index.php?id=3Easier and greater force. [MaxwellBuchanan, Feb 04 2012] curving water a CM from the magnet, rotating ice cubes on a thread http://amasci.com/amateur/neodymium.html [beanangel, Feb 04 2012] Using electric rather than magnetic fields to control hybridisation. http://www.ncbi.nlm...gov/pubmed/10634482 [MaxwellBuchanan, Feb 04 2012] Would the diamagnetism of water be sufficient to produce even piconewtons of force on a lipid-tagged DNA?
I do like the idea of using mechanical force to unzip DNA instead of temperature. However, the patent doesn't present any results that I could see. Interesting, though.-- MaxwellBuchanan, Feb 04 2012 Incidentally, you can get ferromagnetic (or was it paramagnetic) streptavidin-coated particles down to a few tens of nanometres. These can be biotin- coupled to primers, and would be much easier to move magnetically than lipidized DNA.-- MaxwellBuchanan, Feb 04 2012 well a thing on diamagnetic water activities (link) notes that immersing a neodyium magnet at water creates an ongoing curvature difference that focuses light, that this is casually noticeable even when when some really strong magnet is immersed a full CM from the surface.
apparently you can rotate an ice cube on a thread with a neodyium magnets which sounds a little like this application
Im thinking about what [mb] is sayng here though, is the diamagnetism of a few dozen, or hundred (varies with how much DNA) atoms sufficient to create micronewtons of force on that particular DNA polymer strand. I think so, as amount of magnetic flux is arbitrary, also everything from grams to femtoliters of material have been diamagnetically levitated. Is levitating a femtoliter the same as saying 9.8 M/s force on a femtogram.
non calculation: I'm being lazy about 6*10^23 atoms per mole, a few hundred or to be convenient, 1k atoms of DNA, compared with a published levitated femtogram. femto is 15 zeros, 1000 atoms is 3 zeros, levitation is 9.8 m/s/s so a micronewton is perhaps another 3 zeros or more. so its near the 20-23 zeros needed to do 0 to 100 micronewtons on an atom. I know thats nonsense, yet its kinda near the right amount.
as a kind of abstraction, diamagnetic protons (hydrogen) can be accelerated at a cyclotron using magnetism to create particles capable of zipping through hundreds of atoms creating free radicals so it is certainty possible to energize hydrogen atoms diamagnetically to molecule changing strengths. Perhaps a very eentsy separation of pulses multipulse magnetic system could find the naturally occuring "gaps at the zipper" on equalibrium DNA then widen them-- beanangel, Feb 04 2012 Yes, but the forces involved are probably much less than a millinewton (equivalent to 1 gram weight), acting on a large body (several grams) of water. Now scale that to something the size of a few-hundred-basepair DNA molecule, and you're down to something way, way less than a piconewton.
Plus, in your two examples, what you're seeing is the differential between the force on water (small) and the force on either air or oil (zero). Unless DNA behaves very much like oil or air in terms of its response to magnetic fields, you'll get an even smaller force.
I do like the idea of using physical force to control denaturing of DNA, but I suspect that it's much more easily applied using either (a) an electric field or (b) using magnetic nanoparticles attached to the primers.
(Incidentally, the use of electrical forces to control denaturing is baked. There was a company several years ago which used an electrophoretic force to regulate the annealing of DNA to targets on an array.)-- MaxwellBuchanan, Feb 04 2012 Ummm, carry on guys. I'll just sit this one out. Good work though. As you were. (water can be magnetic?) <scuttles off to read links.>-- AusCan531, Feb 04 2012 well, comically, particle accelerators use diamagnetism to accelerate protons (hydrogen) fast enough to make free radicals, so there is a diamagnetic field strength that can separate molecules.
Rather than suggest using a cyclotron I think it might be niftier to use an ionic or zwitterionic fluid to float the DNA or RNA at, if this fluid were nearly as attractive to dna as dna is to dna, then the energy required to spread open zipper gaps would be much less. so I think a clever fluid might be effective
Bismuth is the most diamagnetic element, so its possible that bismuth linked to glycine as a solution with DNA would cause the DNA to sometimes link to the superwiggleable glycine to create then spead zipper gaps
anyway whichever of G,A,T,C is the strongest, make a bismuth version solution, then wiggle it with magnetism to unzip the dna
Its possible that just as cyclotron coincides pulses of energy with location to create movement a really eeeeeennnntsy interval two pulse magnetic field could widen a gap, then widen it again at less time than the typical natural gapping recombination rate.-- beanangel, Feb 06 2012 random, halfbakery