The phrase "a obvious difference between" is not correct.
It should be "an obvious difference between." You can use it when discussing a clear distinction or contrast between two or more things.
Example: "There is an obvious difference between the two products in terms of quality and price."
Alternatives: "a clear difference between" or "a noticeable difference between."
The lack of an obvious difference between the different truncation mutants implied that this phenotype was due to disruption of the acidic cluster at the very C-terminus of the gM cytoplasmic tail (Fig. 1A).
"There's an obvious difference between a good Djibril and a less good Djibril but now we're verging on the old Djibril," said annoying Djibril.
There is an obvious difference between a case in which the plaintiff himself may choose not to proceed, and a case in which the district court refuses to allow the plaintiff to litigate his claim in federal court.
There is an obvious difference between a statute stating the conditions upon which moneys shall be expended and one effective only upon assumption of a contractual obligation to submit to a regulation which otherwise could not be enforced.
P. 73. (9) There is an obvious difference between a statute stating the conditions upon which moneys shall be expended and one effective only upon the assumption of a contractual obligation to submit to a regulation which otherwise could not be enforced.
There is an obvious difference between what a term designates and what it means.
And there's an obvious difference between jokes about a disaster that killed thousands of innocent men, women and children and jokes about the most wanted man in the world being shot in the head by a Navy Seal.
Under mild WD stress, we also observed an obvious difference between the two DTNs for different molecular function categories.
However, the two template-based methods, ThreaDom and FIEFDom, have an obvious difference between 'Easy' and 'Medium/Hard' proteins because of the different availability of the template hits in the two category of proteins.
E.U. ministers, too, were careful to insist that they don't consider their action "a boycott of Israel, which the E.U. opposes"; there is an obvious difference between opposing the Israeli government's policies and opposing the state's existence.
