| abstract |
A method for detecting the presence of a pathogen in a whole blood sample, the method comprising: (a) providing a whole blood sample of a subject; (b) mixing the whole blood sample with an erythrocyte lysis agent to produce destroyed red blood cells; (c) after step (b), centrifuge the sample to form a supernatant and a pellet, discarding part or all of the supernatant, and resuspend the pellet to form an extract, optionally washing the pellet before resuspend the pellet and repeat optionally step (c); (d) lysis the extract cells to form a lysate; (e) placing the lysate of step (d) in a container and amplifying a nucleic acid in the lysate to form an amplified lysate solution comprising the target nucleic acid, wherein the target nucleic acid is characteristic of the pathogen to be detected; (f) after step (e) mixing the amplified lysed solution with 1x106 to 1x1013 magnetic particles per milliliter of the amplified lysed solution to form a liquid sample, wherein the magnetic particles have an average diameter of 700 nm to 950 nm , a T2 relaxation per particle ranging from 1x109 to 1x1012mM-1s-1, and structural bonding unit on its surface, the structural bonding units being operative to alter the aggregation of the magnetic particles in the presence of a target nucleic acid or a multivalent binding agent; (g) placing the liquid sample in a device, the device comprising a support defining a well to contain the detection tube comprising the magnetic particles and the target nucleic acid and having an RF coil disposed around the well, configured the RF coil to detect a signal produced by exposing the liquid sample to a polarized magnetic field created using one or more magnets and an RF pulse sequence; (h) exposing the sample to a polarized magnetic field and an RF pulse sequence; (i) after step (h) measuring the signal of the liquid sample, wherein the liquid sample optionally comprises whole blood proteins and non-target oligonucleotides; and (j) based on the result of step (i) detecting the pathogen, where the pathogen is optionally bacteria or fungi, and where the method is capable of detecting a pathogen concentration of 10 cells / mL in the sample whole blood, preferably where steps (a) to (i) are completed after 3 hours and / or step (i) is carried out without any prior purification of the amplified lysed solution. |