Collection ring for use in multiple-sample blood fractionation centrifugal rotors

Abstract

An improved sample collection ring which comprises a removable annular vial holder ring defining passageways for receiving multiple blood fractions discharged from a central blood fractionation rotor and passing them to respective collection vials. The collection vials sealably and detachably engage respective nipples defined by and integral with the vial holder ring. O-ring seals prevent leakage from the collection vials and assist in the vial-nipple engagement.

Description

BACKGROUND OF THE INVENTION

The invention described herein relates generally to blood fraction preparation systems and more particularly to an improved collection ring for use in multiple-sample blood fractionation centrifugal rotors. It was made in the course of, or under, a contract with the U.S. Atomic Energy Commission.

In clinical blood work, it is necessary to separate stabilized blood samples into plasma and washed cell fractions before many biochemical tests of interest can be performed. For example, photometric analysis may be performed on the plasma fraction only since the presence of red blood cells interferes with the desired absorption measurement.

Genetic monitoring programs to determine mutations in man caused by environmental conditions such as the presence of ionizing radiation, chemical pollutants, etc., as well as other natural causes require the taking, preparation, and analysis of very large numbers of blood samples due to low mutation rates presently postulated. A multiple-sample rotor assembly for blood fraction preparation has been designed to prepare blood fractions without the tedious and time-consuming operations associated with conventional blood fraction preparation techniques. That rotor assembly, which is described in copending application Ser. No. 423,381 of common assignee, uses a removable outer rotor portion defining a plurality of collection chambers for receiving blood fractions discharged from an inner rotor portion. Although the fractionation of blood samples and transfer of fractions to the respective collection chambers are easily achieved using the rotor assembly of the aforementioned patent application, the collected fractions must be individually transferred to separate holders using conventional techniques which are time consuming, laborious, and a potential source of sample contamination.

It is, accordingly, a general object of the invention to provide an improved sample collection ring for use in multiple-sample blood fractionation centrifugal rotor assemblies.

Another object of the invention is to provide an improved sample collection ring for use in multiple-sample blood fractionation centrifugal rotor assemblies wherein the collected fractions may be removed individually from the collection ring without being transferred to separate holders.

SUMMARY OF THE INVENTION

In accordance with the invention, an improved collection ring is provided for use in multiple-sample blood fractionation centrifugal rotors. The collection ring comprises an annular vial holder ring defining passageways for receiving multiple blood fractions from a central blood fractionation rotor and passing them to respective collection vials. The collection vials sealably and detachably engage respective nipples defined by and integral with the vial holder ring. O-ring seals prevent leakage from the collection vials and assist in the vial-nipple engagement. Blood fractions collected in the vials may be individually stored or removed for further processing or testing by simply disengaging the vials from the vial holder ring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, vertically sectioned, showing a multiple-sample blood fractionation rotor incorporating a sample collection ring made in accordance with the invention.

FIG. 2 is a perspective view, vertically sectioned, of the sample collection ring shown in FIG. 1.

FIG. 3 is a section view of the sample collection ring of FIG. 2 showing a secondary collection vial and associated passageways.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, initially to FIG. 1, a multiple-sample blood fractionation centrifugal rotor assembly is shown nested within a motor-driven turntable 1. As shown, turntable 1 is provided with passageways 2 extending from the turntable axis to several points about its periphery. Passageways 2 communicate with a suitable vacuum source for reasons explained below in connection with operation of the rotor assembly.

The rotor assembly includes an inner disk-shaped rotor portion 3 defining a circular array (only one shown) of whole blood sample receiving chambers 4. Static loading ports 5, extending through the top surface of disk-shaped rotor portion 3, facilitate the direct loading of individual whole blood samples into respective sample-receiving chambers 4 under static conditions. Ports 5 are disposed near the centripetal ends of chambers 4 to avoid overflow of chamber contents through the ports during rotation. Other liquids such as washing or hemolyzing liquids may be dynamically distributed to the entire array of chambers 4 by means of a central dynamic distribution port 6 and a multiplicity of distribution passageways 7 communicating between that port and the centrifugal ends of respective chambers 4. Distribution passageways 7 intersect at the periphery of dynamic distribution port 6 to create a saw-tooth or serrated-edge effect which provides a substantially equal distribution of liquid into passageways 7 when the rotor assembly is rotating and liquid is injected into port 6. Transfer passageways 8 extend from a radially intermediate point along the bottom of each chamber 4, radially inward, upward, and then radially outward to the periphery of rotor portion 3 where they act as discharge ports. FIG. 1 is cut away to better illustrate a passageway 8.

Nested concentrically about inner rotor portion 3 is a removable sample collection ring 9 made in accordance with the invention. Collection ring 9 is further illustrated in the perspective and section views of FIGS. 2 and 3. As shown, the collection ring comprises an annular vial holder ring 10 defining a multiplicity of nipples 11 extending from its bottom side. In the preferred embodiment illustrated, pairs of primary and secondary collection vials 12 and 13 are attached in a side-by-side manner to adjacent nipples with one pair of vials being provided for collecting blood fractions from each chamber 4. Conventional rubber O-ring seals 14 prevent leakage of vial contents when they are attached to the nipples as well as assisting in the vial-nipple engagement.

Annular vial holder ring 10 defines a series of liquid entry passageways 15 having enlarged centripetal ends which open in register with the radial extremities of respective transfer passageways 8. Ring 10 is suitably keyed to turntable 1 and/or inner rotor portion 3 to ensure proper alignment of passageways 8 and 15. At its centrifugal end, each passageway 15 extends downwardly through a nipple 11 engaged by a primary collection vial 12. Pairs of primary and secondary collection vials are joined by means of connecting passageways 16 which are also formed in vial holder ring 10. As shown, passageways 16 extend between adjacent nipples engaged by a pair of primary and secondary collection vials, thereby providing liquid communication between those vials. Liquid blood fractions discharging from transfer passageways 8 fill the respective primary collection vials 12 and then overflow through passageways 16 into secondary collection vials 13. A third series of passageways 17 extend between those nipples engaged by the secondary collection vials to the top surface of ring 10 near its inner periphery. Passageways 17 provide an escape route for air displaced from vials 12 and 13 and vacuum application means for activating liquid transfer from rotor portion 3 to the collection ring.

As shown in FIG. 1, a vacuum annulus 18 is formed above collection ring 9 and the adjoining inner rotor portion 3 by means of an annular sealing disk 19 positioned between upstanding rim 20 of turntable 1 and a raised flange 21 formed on the top surface of inner rotor portion 3. O-rings 22 provide the necessary vacuum seal while permitting removal of the entire rotor assembly from the turntable. Evacuation of vacuum annulus 18 is accomplished by means of passageways 2 which extend from the axis of turntable 1 to several points about its periphery in communication with the annulus.

OPERATION

Using a rotor, collection ring, and turntable substantially as previously described in reference to the drawings, stabilized whole blood samples are first loaded through ports 5 into respective sample-receiving chambers 4 with the rotor at rest. Following loading, the turntable is rotated at high speed until the blood cells and plasma within the rotor are separated. At this point the rotor is slowed and vacuum applied through passageways 2 to provide a reduced pressure in annulus 18. This causes a reduced pressure to be developed in passageways 8, 15, 16, and 17 and in vials 12 and 13 since they are all in communication. The higher pressure (atmospheric) present in chambers 4 relative to that in passageways 8 forces the plasma in those chambers to pass through passageways 8 to respective passageways 15 and primary collection vials 12. Depending upon the amount of plasma initially present in chambers 4, primary collection vials 12 may be filled and overflow through passageways 16 into secondary collection vials 13. The rotor assembly is then stopped, sample collection ring 9 removed from the turntable-rotor assembly, and individual sample collection vials removed from the collection ring for testing or storage of their contents. Recovery of cell hemolysate may be accomplished in a second collection ring using techniques taught in copending application Ser. No. 452,164 of common assignee.

The above description of one embodiment of the invention should not be interpreted in a strictly limiting sense. For example, although the sample collection vials are shown grouped in pairs, a single vial could be used for receiving liquid discharged from each passageway 8. A larger number of interconnected vials could also be used. It is intended, rather, that the invention be limited only by the scope of the appended claims.

Claims

What is claimed is:

1. An improved sample collection ring for use in multiple-sample blood fractionation centrifugal rotors characterized by a central rotor portion for preparing blood fractions having a multiplicity of circumferential discharge ports; said collection ring comprising:

i. a removable annular vial holder ring having a top surface and a bottom surface nested concentrically about said central rotor portion, said vial holder ring defining:

a. first and second nipples positioned alternatively in a circular array, said nipples depending from the bottom side of said vial holder ring;

b. a first array of passageways having centripetal ends opening in register with said circumferential discharge ports and centrifugal ends opening in the bottom ends of said first nipples;

c. a second array of passageways communicating between and opening in the bottom ends of pairs of said first and second nipples; and

d. a third array of passageways having centrifugal ends opening in the bottom ends of said second nipples and centripetal ends opening in said top surface of said vial holder ring;

ii. primary and secondary sample collection vials removably attached to said first and second nipples, respectively; and

iii. means for sealing said sample collection vials to said nipples.

2. The improved sample collection ring of claim 1 wherein the centripetal ends of passageways in said first array of passageways have enlarged ends.

3. The improved sample collection ring of claim 1 wherein said means for sealing said sample collection vials to said nipples comprises O-rings extending circumferentially about said nipples.

4. An improved sample collection ring for use in multiple-sample blood fractionation centrifugal rotors characterized by a central rotor portion for preparing blood fractions having a multiplicity of circumferential discharge ports; said collection ring comprising:

i. a removable annular vial holder ring having a top surface and a bottom surface nested concentrically about said central rotor portion, said vial holder ring defining:

a. a circular array of nipples equal in number to said discharge ports, said nipples depending from the bottom side of said vial holder ring;

b. a first array of passageways having centripetal ends opening in register with said discharge ports and centrifugal ends opening in the bottom ends of said nipples; and

c. a second array of passageways having centrifugal ends opening in the bottom ends of said nipples and centripetal ends opening in said top surface of said vial holder ring;

ii. sample collection vials removably attached to each of said nipples; and

iii. means for sealing said sample collection vials to said nipples.

5. The improved sample collection ring of claim 4 wherein said means for sealing said sample collection vials to said nipples comprises O-rings extending circumferentially about said nipples.