US 11,927,595 B2
Immunoassay for free vitamin D
Michaël Franciscus Wilhelmus Cornelis Martens, Helmond (NL); George Henry Parsons, Arlington, MA (US); Franciscus Maria Anna Rosmalen, Wijchen (NL); and Leon Maria Jacobus Wilhelmus Swinkels, Bemmel (NL)
Assigned to FUTURE DIAGNOSTICS B.V., (NL)
Filed by Future Diagnostics B.V., Wijchen (NL)
Filed on Jan. 15, 2021, as Appl. No. 17/150,850.
Application 15/862,318 is a division of application No. 13/638,613, granted, now 9,897,615, issued on Feb. 20, 2018, previously published as PCT/NL2011/050219, filed on Apr. 1, 2011.
Application 17/150,850 is a continuation of application No. 15/862,318, filed on Jan. 4, 2018, granted, now 10,935,557.
Claims priority of application No. 10159035 (EP), filed on Apr. 1, 2010.
Prior Publication US 2021/0132087 A1, May 6, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G01N 33/82 (2006.01); G01N 1/28 (2006.01); G01N 33/53 (2006.01)
CPC G01N 33/82 (2013.01) [G01N 33/5308 (2013.01); G01N 1/28 (2013.01)] 15 Claims
 
1. A method for assaying a sample of blood or blood components for the presence of free vitamin D comprising:
(a) adding an immobilized binding protein or antibody for 25-OH vitamin D to the sample;
(b) mixing the sample with a diluent, said diluent comprising a fluoroalkyl surfactant;
(c) incubating the sample for an effective amount of time to allow a desired amount of vitamin D to bind to the immobilized binding protein or antibody;
(d) removing non-bound serum and serum components by washing;
(e) subjecting the immobilized binding protein or antibody comprising captured vitamin D bound thereto to competitive binding with a labeled vitamin D compound;
(f) determining the concentration of labeled vitamin D compound bound to the binding protein,
wherein the fluoroalkyl surfactant does not dissociate vitamin D from vitamin D binding protein and albumin, and wherein the concentration of the surfactant is 0.05 to 0.5% by weight.