The phrase "a single stretch of" is correct and usable in written English.
It can be used to describe a continuous length or area of something, often in the context of physical space or time.
Example: "The marathon route included a single stretch of road that was particularly challenging for the runners."
Alternatives: "a continuous length of" or "an uninterrupted span of".
It turns out, for example, that several different proteins may be produced from a single stretch of DNA.
Hidden beneath overhanging trees and marked only by overgrown restaurant signs measuring the metres to your next meal, a single stretch of restaurants showcase Brazil's huge cultural diversity.
The agency does not keep track of casualty figures for a single stretch of road when its limit rose to 70 from 55.
Texas tried to keep track of a single stretch of road, starting in January 1996, when highway speeds reverted to a daytime 70 m.p.h. and 60 at night.
Pupusas are everywhere in Washington, but nowhere does the concentration of cheese-filled tortillas seem greater than on a single stretch of University Boulevard in Maryland.
Instead, for whatever reason, as the Free Press noted, a quarter of the remaining samples "came from a single stretch of Flushing Road in Flint," which had a water-main section only a few years old.
Its beach is a long, single stretch of ultra-fine golden sand.
The single stretch of bars, shops and clubs seemed to be competing to see which could have the ugliest display of flashing fairy lights in the window.
The Corps of Engineers, meanwhile, is studying how to protect the biggest single stretch of Long Island's barrier islands -- the 83 miles from Fire Island east to Montauk Point.
Trump loves to take digs at NATO, the alliance responsible for the longest single stretch of peace in the United States and Europe in modern history.
So, Dr. Gingeras argues, we can no longer think of genes as being single stretches of DNA at one physical location.
