String repair

Proteins help to compact DNA this is important because the DNA in a chromosome could not fit inside its cell if it were not compacted. Histones are positively charged proteins that neutralize negative DNA strands when they wrap around and form complexes with the DNA. This wrapped structure, called beads on a string, represents the first level of compaction. The beads are condensed to form fibers, fibers fold into loops, loops combine with nuclear scaffold proteins to form rosettes, and rosettes condense to form coils. Finally, a chromatid with ten or more coils is formed. Nonhistone proteins within chromosomes are also important. These proteins have varied functions, including assisting in the unwinding of DNA and in the repairing of DNA. 

In the past models that could have originated in toy boxes (i.e., strings, balls, beads, spheres, etc.) or configurations out of car repair shops (Le., crankshafts, springs, coils, screws, dash pots, bricks, spaghetti, etc.) have been employed. 

Continuous injection is generally the best method, if it can be applied. Inhibitor is always present to repair places where the old inhibitor has been removed. Some wells are completed with parallel strings, concentric strings, and U-tube-type strings. If the well will support the column of inhibited fluid (parallel and concentric completions), then continuous injection can be accomphshed. In most cases, a U-type completion will have a back pressure valve toward the bottom of the small string and can be loaded with the inhibited fluid. 

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