US 12,290,765 B2
Materials and methods for processing blood samples
Aoy Tomita Mitchell, Elm Grove, WI (US)
Assigned to Natera, Inc., San Carlos, CA (US)
Filed by Natera, Inc., San Carlos, CA (US)
Filed on Feb. 20, 2024, as Appl. No. 18/582,572.
Application 18/582,572 is a continuation of application No. 16/839,319, filed on Apr. 3, 2020, granted, now 11,931,674.
Claims priority of provisional application 62/829,320, filed on Apr. 4, 2019.
Prior Publication US 2024/0350945 A1, Oct. 24, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B01D 21/26 (2006.01); B01L 3/00 (2006.01); B04B 5/04 (2006.01)
CPC B01D 21/262 (2013.01) [B01L 3/5082 (2013.01); B04B 5/0414 (2013.01)] 14 Claims
 
1. A method for quantifying cell-free DNA, the method comprising:
(a) providing a tube comprising
an outer wall and a base defining an internal volume for containing a blood sample;
a chemical preservative disposed in the internal volume, wherein the chemical preservative comprises one or more of metaformaldehyde, paraformaldehyde, poloxamer, glycerol, propranolol, dex-propranolol, methacrylate monomer, methacrylate polymer, or bis-dienoyl phosphatidylcholine;
a physical separator disposed in the internal volume, wherein the physical separator substantially separates the blood sample into at least a plasma component and a blood cell component when the tube is centrifuged and prevents aspiration of the blood cell component during subsequent isolation of the plasma component from the tube; and
a blood sample disposed in the tube;
(b) centrifuging the tube at a first fixed speed to separate the blood sample into at least a plasma component and a blood cell component;
(c) isolating the plasma component;
(d) centrifuging the isolated plasma component at a second fixed speed to obtain a purified plasma component, wherein the first fixed speed and the second fixed speed are each independently selected from a speed ranging from 500×g to 2000×g; and
(e) quantifying cell-free DNA present in the further purified plasma component.