Provided herein are materials and methods relating to cell-free DNA. In particular, the technology relates to methods and materials for the preparation and handling of blood samples for future use in applications involving cell-free DNA.

The invention relates to a centrifuge (10) for automatic loading, having a drive shaft (44), which is driven in a rotatable manner about a rotor axis (42), having a rotor (46), which is releasably coupled for conjoint rotation to the drive shaft (44) and has mounts for containers for media to be centrifuged, having a housing (12) with lateral outer walls (14, 16, 18, 20) delimiting the centrifuge (10) and with a ceiling (22), wherein at least one outer wall (14) has a sideways directed side opening (28) for loading the rotor (46) as required, and having a safety vessel (50) with at least one partially enclosing protective wall (34), which is adapted at least to the shape of the adjacent outer wall (14) with side opening (28) such that said protective wall closes off the side opening (28).

A fixed-angle rotor for centrifuges includes stiffening ribs on the lower side of its rotor body. Its rotational energy is comparatively low during operation even at high speeds, whereby safety is noticeably increased without the need for a reinforced armored vessel in the centrifuge that is equipped therewith. At the same time, the drive power required to drive the fixed-angle rotor remains low. The fixed-angle rotor also withstands extreme loads over a long period of time. In addition, the fixed-angle rotor can be manufactured cost-effectively, because no additional components are required; rather, the stiffening ribs can also be manufactured during the manufacture of the rotor body. Finally, very thin rotor shells can also be used, which improves the temperature control of the samples, because the fixed-angle rotor has very good structural stability, especially in the main load directions.

A rotor for use in a centrifuge, and adapters for coupling one or more processing containers to the rotor. The rotor includes a rotor body having a plurality of receptacles each configured to receive an adapter. Each adapter includes an outer surface configured to interface with one of the receptacles, and one or more cavities each configured to accept a processing container. The rotor may also include a rotor liner positioned between the adapters and the rotor body. The rotor liner engages the receptacles of the rotor body, and provides a plurality of receptacles that receive the adapters, thereby providing an interface between the adapters and the receptacles of the rotor body.

A portable motorized centrifugal system is optimized for low cost manufacture and operation. Separation of inhomogeneous fluid biological samples, such as liquid plasma from whole blood, is a common step in medical diagnostic tests. This system may enable remote separation where access to plug-in power sources are limited. The system may facilitate at-home testing. Due to biohazard concerns, the entire centrifugal apparatus portable and disposable, or the system includes one or more disposable elements within the interior of the centrifuge. Alternatively, the system may contain a module of higher value components that are re-usable after disinfection. Devices and methods for implementing centrifugal separation may include disk-shaped fluidic cartridges and tubes with reduced drag cross-section.

Apparatus and methods for separating blood components are disclosed in which an apparatus for separating blood generally includes a tube defining a channel and configured for receiving a quantity of blood and a float contained within the tube and having a density which is predefined so that the float is maintained at equilibrium between a first layer formed from a first fractional component of the blood and a second layer formed from a second fractional component of the blood. Upon completion of the centrifugation, the first layer may be removed from the tube while the float isolates the second layer from the first layer.

A rotor assembly that includes a fixed-angle rotor with a plurality of rotor wells that each have a central axis in a fixed angular relationship relative to a rotational axis of the rotor to define a rotor well angle for each rotor well, and further includes an adapter for use with one of the rotor wells. The adapter includes a body with a circular cross-sectional shape that extends between a first end and a second end, and a sample tube cavity formed in the body. The cavity extends from an opening at the first end of the body to a closed base at the second end of the body and includes a longitudinal axis. When the adapter is positioned within the rotor well, the longitudinal axis of the cavity has an angular relationship relative to the rotational axis of the rotor that is different compared to the rotor well angle.

A magnetic bead separation method includes: storing, in a container, a mixed liquid containing a magnetic bead and a liquid containing target molecules, and adsorbing the target molecules on the magnetic bead, the magnetic bead containing a Fe-based metal soft magnetic particle and a coating film with which the Fe-based metal soft magnetic particle is coated, and having a saturation magnetization of 50 emu/g or more and 250 emu/g or less; applying an external magnetic field to the container and magnetically attracting at least a part of the magnetic bead by the external magnetic field; and applying an acceleration to the container while the magnetic bead is magnetically attracted by the external magnetic field and desorbing the liquid adhering to the magnetic bead.

A centrifuge rotor for sample vessels includes a seal between a lower part and a cover. The seal comprises a gasket, which is arranged in a first groove. The first groove is arranged on one of the elements constituted by the cover and the lower part. The first groove, in relation to the axis of rotation of the centrifuge rotor, is open axially toward the other of the elements constituted by the cover and the lower part.

Embodiments of a portable and compact centrifugal system with methods of energy efficient centrifugation are described. The centrifugal system may be used to separate biological samples contained in conventional laboratory tubes and may be powered by a set of battery cells. The centrifugal system may comprise a vibration damping system which may comprise a tuned mass damper with a damper mass, a damper wall, and an elastic coupler. Many features such as the device's voltages, vibration damping methods, firmware, circuitry, component placement, and material required careful consideration, experimentation, and selection to converge into a functional product. Centrifugation of biological samples typically requires bulky instruments that cannot be readily moved, which can prove inconvenient for remote areas and third world countries. Biological sample quality also degrades outside the body over time, so immediate access to a centrifugal system can improve sample quality.