Wht can't blood be collected contained by tubes containing fluoride as preservative and anticoaugulant?

Wht can't blood be collected contained by tubes containing fluoride as preservative and anticoaugulant?
There is a certain tube that have sodium fluoride compound in it. That simply mode there is a fluoride surrounded by it.
The tube contains potassium oxalate as an anticoagulant and sodium fluoride as a preservative - used to preserve glucose in full blood and plasma analyses for acetone, and alcohols.
Every different tubes have other specific preservative and anticoagulants to maintain the the particular blood components unaltered thus obtain accurate results.
Flouride helps tooth enamel and is sheltered if ingested. I doubt it's as safe contained by the bloodstream (not really sure,) and it's not a preservative in the sense of extending efficacy or shelf life span.
You are referring to the "gray tops" that contain fluoride and oxalate. The fluoride is not a preservative relative to microbes. It inactivates enzymes that digest glucose in the indication. The oxalate is the anticoagulant. These will interfere with several assays. Because of the anticoagulant, no assay can be run where the anticoagulation will reverse and a clot will foul the assay. The fluoride may be misinterpreted within other assays, or may inactivate the enzymes used to make such assessments.