The phrase "available only a single" is not correct in English.
It should be "available only as a single" or "available only in a single format." You can use it when referring to something that is offered in just one option or version.
Example: "The song is available only as a single, not as part of an album."
Alternatives: "offered only as a single" or "accessible only as a single.".
Since small volumes (∼100 µL) of the individual rabbit sera were available, only a single antibody sample, representing a pool of IgGs from the 98 rabbits, was available for in vitro growth inhibition assay.
Among the 44 superior segregants available, only a single such segregant, 26B, was present.
Furthermore, out of the many bacterial rbcL sequences now available, only a single organism, Rhodobacter azotoformans, has been found that contains both red-like and green-like rbcL [ 54], and this is clearly due to a bacterial HGT event instead of retention of both copies from an ancient duplication.
If data were available only for a single pair of examiners at a single encounter it would not be possible, when examiner A marks a candidate lower than does examiner B, to tell whether A is more hawkish or B more doveish on average.
But more than 60percentt of the 50 most frequently used drugs, including antibiotics and medication to treat high blood pressure, are still available only from a single source.
To help persuade the F.D.A. to approve Xyrem, Orphan Medical agreed to make the drug available only from a single pharmacy in Missouri, which ships it to patients nationally.
The concept of magazines available only at a single retailer dates to at least 1931, when Woman's Day began as a menu sheet at supermarkets owned by the Great Atlantic and Pacific Tea Company.
Other information sources like the outside temperature, humidity, or irradiation are available only for a single industry (if it is regarded at all).
In South Africa all varieties of insulin are biosynthetic and available only as a single strength, 100 units/ml.
25 The differing efficacy by vaccine type might reflect a chance occurrence, as data on effectiveness of RV5 in Latin America are available only from a single country.
However, nafenopin data were available only at a single dose of 500 ppm (Lake et al. 1993), which we linearly interpolated to the TD50.
