Liquid sample collection device for zonal centrifugation

A centrifuge comprising a zonal rotor, a centrifuge chamber having a side wall and a bottom wall to contain the zonal rotor, an upper shield to cover the top of the centrifuge chamber and enclose the zonal rotor, and an annulus in the centrifuge chamber that is laterally spaced apart from the zonal rotor. The annulus has a channel with a base and a lip, where the channel has an open end facing the direction of the upper shield to collect liquid sample leaked during loading or unloading the zonal rotor.

BACKGROUND OF THE INVENTION

The present invention pertains generally to a liquid sample collection device for use in the process of zonal centrifugation. The device captures liquid sample that may spill or leak during the process of loading or unloading liquid sample while the rotor is spinning. This prevents the leaked liquid sample from coming into contact with sensitive components inside the centrifuge chamber, thereby protecting the centrifuge from damage.

In the process of zonal centrifugation, the centrifuge rotor is loaded and unloaded with liquid sample while the rotor is spinning. During the loading and unloading of liquid sample, it is difficult to maintain a complete, tight seal between the spinning rotor and the stationary sample-loading apparatus. Consequently, some of the liquid sample may leak into the centrifuge chamber during the loading or unloading of the zonal rotor. The centrifugal force of the spinning rotor tends to propel this leaked liquid outward towards the wall of the centrifuge chamber. This leaked liquid may then flow down the wall of the centrifuge and settle on the bottom of the centrifuge chamber where it may come into contact with sensitive electronic or mechanical components of the centrifuge causing damage to the centrifuge.

It is therefore desirable to prevent damage to a centrifuge caused by exposure to liquid sample that leaks into the centrifuge chamber during the loading and unloading of a rotor during zonal centrifugation. The present invention provides a liquid sample collection device that captures this leaked liquid, thereby preventing damage to the centrifuge.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a liquid sample collection device that captures leaked liquid sample during the process of loading or unloading of a zonal rotor. The top of the device supports the liquid sample fill head of the zonal rotor. The top and side interior walls of the device provide containment for leaked liquid sample that is propelled outward due to centrifugal force of the spinning rotor. A lip at the bottom of the device forms a channel to collect the liquid sample that flows down the walls of the device. The sample collection device is removed from the centrifuge after loading or unloading of the zonal rotor, thereby removing the leaked liquid sample from the chamber and preventing the leaked liquid sample from coming into contact with sensitive components inside the centrifuge chamber.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a device for capturing liquid sample that leaks during the loading or unloading of a zonal rotor. The device prevents leaked liquid sample from collecting on the walls of the centrifuge chamber and from coming into contact with sensitive electrical or mechanical components inside the centrifuge. An advantage is the prevention of damage to the centrifuge that may arise due to contact of the leaked liquid sample with sensitive components inside the centrifuge. Another advantage is the prevention of liquid accumulation on the walls of the centrifuge chamber that may interfere with obtaining the proper vacuum inside the chamber during centrifugation.

DEFINITIONS

A liquid sample fill head is a fixture including ball bearing and rotating/stationary seal that is used to load and unload sample into/out-of a spinning zonal rotor.

A zonal rotor is a centrifuge rotor that can be loaded and unloaded with sample while spinning for the process of zonal centrifugation.

Loading of a zonal rotor means adding sample to a zonal rotor while the rotor is spinning at a rotor loading speed.

Unloading of a zonal rotor means removing sample from a zonal rotor while the rotor is spinning at a rotor unloading speed.

FIG. 1illustrates a liquid sample collection device10, an embodiment of the present invention, arranged in a centrifuge12. The arrangement includes the liquid sample collection device10disposed about a zonal rotor14and a liquid sample fill head16inside a centrifuge chamber18. A support band22, which may be a metal ring, is located on the inside of the centrifuge chamber18to position the liquid sample collection device10at the correct location relative to the zonal rotor14. In the illustrated embodiment, tabs21project outward from generally the top outer edge of the liquid sample collection device10, and corresponding slots25are located on the support band22. The tabs21fit into the slots25to position and hold the liquid sample collection device10at the correct location relative to the zonal rotor14. The tabs21may be retractable to facilitate the insertion of the tabs21into the slots25. Although the embodiment depicted inFIG. 1discloses a metal support band22with slots25, the support band22can be any suitable structure for holding and positioning the liquid sample collection device10. The liquid sample fill head16may be installed onto the liquid sample collection device10for the loading and unloading of the zonal rotor14with liquid sample while the zonal rotor14is spinning.

In a preferred embodiment, the liquid sample collection device10includes an upper shield24, a vertical wall26, a base28, and a lip32. In the illustrated embodiment, the upper shield24is a circular plate with a central hole34. The central hole34facilitates the liquid sample fill head16to attach to the zonal rotor14or to hold the liquid sample fill head16during the loading and unloading process. A bracket33with opposed fingers37is attached to the top of the upper shield24and is centered over the central hole34. Locking grooves17are formed in opposite sides of the liquid sample fill head16. The locking grooves17engage the opposed fingers37to install and reversibly lock the liquid sample fill head16into position on the upper shield24for loading and unloading the zonal rotor14.

The vertical wall26is generally a cylinder that extends downward from about the outer radial edge of the upper shield24. The base28depends toward the zonal rotor14and the lip32extends vertically from the base28. Arranged this way, the vertical wall26, base28and lip32form a channel36where liquid sample that leaks from the liquid sample fill head16during loading or unloading of the zonal rotor14is contained by the upper shield24and the vertical wall26, and is collected in the channel36. The upper shield24prevents leaked sample from being expelled upward out of the centrifuge, while the vertical wall26contains and captures leaked sample that is propelled outward by the centrifugal force of the spinning rotor14. Contained liquid sample that flows down the vertical wall26collects in the channel36. The containment of leaked liquid sample by the upper shield24and the vertical wall26, and the collection of leaked liquid sample by the channel36prevents leaked liquid sample from accumulating inside the chamber18of the centrifuge12. In the absence of such a containment and collection device, leaked liquid sample may come into contact with instrument electronics located underneath the refrigeration can, or with the centrifuge drive, resulting in component or drive failure.

In one embodiment, the upper shield24, the vertical wall26, the base28and the lip32are made from plastic. However, these parts may be made from any suitable material.

Also, in a preferred embodiment, the vertical wall26, the base28and the lip32are molded as a one piece annulus38.

In another embodiment, the vertical wall26is composed essentially of a stack of multiple cylindrical pieces.

After loading the zonal rotor14with sample, the liquid sample collection device10can be removed from the centrifuge12by disengaging the tabs21from the slots25and lifting the liquid sample collection device10off of the support band22, thereby removing the collected leaked liquid sample from the centrifuge12before a vacuum is applied to the centrifuge chamber18, the rotor is spun at a rotor centrifugation speed, and the centrifugation run is completed. An advantage is that the liquid sample collection device10, being removable, does not interfere with temperature control during centrifugation. Likewise, the liquid sample collection device10can be removed after unloading the zonal rotor14, thereby removing the collected leaked liquid sample from the centrifuge12. The rotor centrifugation speed may be greater than the rotor loading speed.

In a preferred embodiment, a drain hole42is formed in the base28(FIG. 10). A plug44reversibly seals the drain hole42to provide for the removal of collected fluid from the liquid sample collection device10after the liquid sample collection device10has been removed from the centrifuge12.

In another preferred embodiment, a piloting feature46extends outward from the upper circumference of the upper shield24(FIG. 11). The piloting feature46facilitates the installation and the positioning of the liquid sample collection device10in the centrifuge chamber18by guiding the liquid sample collection device10in essentially straight upwards or straight downwards movement when the liquid sample collection device is installed into or removed from the centrifuge chamber18, thereby avoiding contact of the liquid sample collection device10with the spinning zonal rotor14.

In another preferred embodiment, the liquid sample collection device10includes a projection52extending generally outwards from the top of the lip32towards the vertical wall26(FIG. 10). The projection52serves to narrow the opening to the channel36, thereby reducing the chance of spilling liquid sample out of the channel36when the liquid sample collection device10is removed from the centrifuge12.