The phrase "a single test that" is correct and usable in written English.
You can use it when referring to one specific test that is being discussed or analyzed in a particular context.
Example: "The study focused on a single test that measures cognitive abilities in children."
Alternatives: "one test that" or "a lone test that".
"It's important to have a single test that can differentiate between the four serotypes of Dengue and Zika, because they co-circulate.
For routine diagnostics a single test that is able to detect and type a range of cestodes is preferable.
Examiners will struggle too, to produce a single test that measures the same level of ability in children of different ages.
Consider now the question sheets and the completed answer sheets that make up a single test that has been administered to millions of students at about the same time.
But now scientists with the Agricultural Research Service of the United States Department of Agriculture report significant advances toward a single test that can detect both pathogenic E. coli and its toxins.
When both studies were combined, approximately 20% of nonpregnant cows could be identified with a single test that was done before or shortly after AI with a false positive rate of less than 5%.
There is no single test that provides a conclusive diagnosis of white guilt, but a combination of the following tests can be informative: Treatment Unfortunately, given the existence of Steve Bannon, white guilt is at an all-time high, and doctors are still in search of a cure.
There is no one single test that can confirm a diagnosis of PCOS.
After 200 years, it had passed every single test that was thrown its way.
No single test that a clinician uses makes the diagnosis.
The paper-and-pencil version was administered to the students using a single test form that consisted of the same items in the same positions.
