Principles Of Detection

The principle underlying the comet assay is the increased electrophoretic migration of DNA upon formation of strand breaks or nicks.[1,2] To allow DNA migration, the agarose-embedded cells undergo a lysis process that eliminates cytoplasm, cellular membranes, and DNA-associated proteins such as histones. The naked DNA left in the gel retains its original nuclear shape and supercoiled arrangement, and is referred to as ''nucleoid.'' The undamaged nucleoid cannot migrate in an electric field because of its high molecular weight and compact structure. However, if breaks are present in the DNA molecule, the supercoil relaxes to some extent, and loops or free ends can be pulled out of the nucleus. It has been proposed that in the neutral version mainly loop migration takes place, unless the frequency of double-strand breaks (DSBs) is high enough to generate fragments that can move out of the nucleus.[3] In the alkaline comet assay, both relaxed loops and fragment migration take place, with the fragments being completely or partially single stranded, depending on breakage frequency.[3,4]

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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