US 3796542 A
A multipurpose molded centrifuge tube formed from that type of plastic that is transparent upon completion of molding and includes a body shaped as a bellows-folded helix having a closed bottom and a syringe tip at its top. The tube is used to collect, centrifuge and dispense liquid specimens as incidents to laboratory test procedures; and the transparency of the tube additionally enables its use when exposed to heat for the visual qualitative determination of the presence of certain theretofore undisclosed compounds in the liquid specimen, such as albumin in urinanalysis.
Description (OCR text may contain errors)
United States Patent 1 A A 1 65 1 Kline v a [451 Mar. 12, 1974  USE OF MULTI-PURPOSE CENTRIFUGE 3,582,283 6/1971 Mirasol, Jr 23/292 X E 1 BIOLOGICALv ANALYSIS 3,684,453 8/1972 Lartigue et al. 23/292 X  Inventor: William M. Kline, Gloversville, NY.
 Assignee: Medical Evaluation Devices &
- Instruments C0rp., Gloversville,
Primary Examiner-Morris O. Wolk Assistant ExaminerR. E. Serwin v Attorney, Agent, or Firm-Thomas E. Tate '22 Filed: Dec. 13, 1971 21 1 Appl. No.: 207,447 r 57 ABSTRACT Related Appficafion Data I h A multipurpose molded centrifuge tube formed from Coniinuatiofleimpflfl 9 60354, A gthat type of plastic that is transparent upon comple- P tion of molding and includes a body shaped as a bellows-folded helix having a closed bottom and a syringe  US. Cl. ;3 /230 B, 23/259, 23/292, I tip at its top The tube i used to collect centrifuge 4 128/2 F and dispense liquid specimens as incidents to labora- [5 Cl. l t y t t p d d t p y f th t b  Field of Search 23/259, 292, 230 B, 230 R; additionally enables its use when exposed to heat for 123/2 128 i the visual qualitative determination of the presence of certainltheretofore undisclosed compounds in the liq- 1 References C'ted uid specimen, such as albumin in urinanalysis. I
UNITED STATES PATENTS 3,532,470 lO/l970 Rochte 23/292 X 1 Claim, 4 Drawing Figures USE OF MULTI-PURPOSE CENTRIFUGE TUBE IN BIOLOGICAL ANALYSIS RELATED APPLICATION This application is a continuation-in-part of my copending application Ser. No. 60,354, filed Aug. 3, 1970 (now Pat. No. 3,712,295 granted .Ian. 23, 1973) for Centrifuge Tube.
THE INVENTION This invention relates generally to new and useful improvements in laboratory equipment and particularly seeks to provide a novel multipurpose centrifuge tube formed from a plastic that is transparent upon completion of the tube-forming operation.
In certain diagnostic procedures, such as the PAP test for cancer of the cervix, the area to be tested is irrigated with a saline or other solution which is then withdrawn and centrifuged to separate the solids which are decanted for subsequent reagent or other analysis.
Such procedures may be greatly simplified through the use of a centrifuge tube constructed in accordance with the invention disclosed and claimed in said related Pat. application Ser. No. 60,354, wherein the tube contains the irrigating solution and initially serves as a syringe to collectthe specimen.
I have now discovered that if such centrifuge tubes are fabricated from a plastic material that becomes transparent upon completion of fabrication of the tubes, certain additional advantages accrue with respect to their end use possibilities. For example, and in addition to the normal threefold functions of such cave hollows that may serve as abutments for the posi' tioning of the tube in a centrifuge and/or as abutments for the mechanical axial partial collapsing of the tube in subsequently used processing apparatus.
A further object of this invention is to provide a centrifuge tube of the character stated that is simple in design, rugged in construction and economical to manufacture.
With these and other objects, the nature of which will be apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.
In the drawings:
FIG. l is a side elevation of a centrifuge tube con- ,structed in accordance with this invention;
. through the bottom for discharge of the concentrated tubes (collecting syringe, centrifuge tubeand dispensfor that purpose. In other words, it is no longer necessary to collect the sample in one syringe and transfer it to another container for water bath heating and possibly to still another container for centrifuging or other subsequent procedures.
Therefore, an object of this invention is to provide a transparent centrifuge tube formed from a smooth, in-
ert,'flexible plastic having a memory, and having a syringe tip'at its top and a sealed bottom.
Another object of this inventionis to provide a centrifuge tube of the character stated in'which the body is formed as a bellows-folded helix to direct the flow of solid particles to the bottom when vortex mixed or when centrifuged.
Another object of this invention is to provide a centrifuge tube of the character stated in which the bottom may be pierced by a double tipped needle after vortex mixing or after centrifuging to produce a positive acting syringe to discharge the concentrated solids for subsequent examination.
A further object of this invention is to provide a centrifuge tube of the character stated in which the sealed bottom is tapered by two diametrically opposed conmaterial following vortex mixing or centrifuging;
FIG. 3 is a fragmentary section. of the tip thereof when used asa hypodermic needle for the collection of fluid samples from beneath the skin; and
FIG. 4 is a schematic view showing the immersion of a tube in a water bath for heating the contents thereof as directly collected from a patient. I
Referring to the drawings in detail, the invention, as illustrated, is embodied in a transparent centrifuge tube generally indicated 5 formed from an inert molded plastic such as a polyethylene, polypropylene or polyurethane having a memory and having the characteristic of transparency when molded into a finished object and includes a hollow body 6, formed as a helix of say, four to sixteenturns from top to bottom.
The bottom is tapered as at 7, 7 by two diametrically opposed concave hollows that may serve as abutments for positioning the tube in a centrifuge and/or as abutments for the mechanical axial partial collapsing of the tube to discharge a portion of its contents into subsequently used processing apparatus. The bottom is closed by amembrane 8 and the top is provided with an axially extending hollow tip or cannula that extends into open communication with the interior of the body 6 and is, of course, sufficiently long to reach that portion of a patients body cavity from which a specimen is to be collected. The tip 9 may be covered by a friction cap (not shown) or other suitable closure to maintain same sterile-until use, it being understood that the interior of the body 6 is already sterile due to its exposure to heat above sterilizing temperatures during formation of the tube.
In preparation for use in diagnostic tests, such as the above mentioned PAP test, the body 6 is filled with the desired saline or other solutionby immersing the tip 9 in a supply thereof andaxially collapsing and releasing the body 6 to draw in a quantity of the solution by vacuum, after which the tip is closed.
At the point of use, the tip is uncovered and inserted into the proper body cavity which becomes irrigated as the result of using the body 6 as a positive and negative acting syringe, thus collecting the required specimen for examination. Afterthe specimen has been collected the tube and its contents are transferred to a centrifuge where the solids are concentrated adjacent the bottom 8. The helices of the body 6 expedite the flow of solids toward the bottom during centrifuging or vortex mixing, thus assuring proper concentration of the solid s in a substantially uniform distribution.
For subsequent examination and analysis of the collected solids it is only necessary to extract a portion of same by piercing the bottom membrane 8 with a double ended needle 10 (see FIG. 2) and partly collapse the body 6 along its axis to positively eject the specimen onto a slide or other analytical receiver. The tip 9 will of course be closed during this latter operation in order to prevent loss of pressure within the body 6.
In FIG. 3 of the drawings there is shown a modification that enables the centrifuge tube of this invention to be used for the subcutaneous collections of samples of blood or other body fluids. To this end a hypodermic needle 11 is molded in place at the top of the body 6 and is protected by a friction cap 12.
Since the material of the body has a memory, this modification may be shipped in an axially collapsed condition (held by a suitable clamp or restraining bracket, not shown) to the point of use where the cap 12 is removed, the needle 11 is inserted under the skin after which the restraining clamp is removed to permit the tube body to expand axially to its normal position and draw the fluid sample thereinto through the needle.
For the typical end uses thus far described for this centrifuge tube, it-is not necessary for it to be transparent. It needs only to be sufficiently translucent that the level of the initially collected specimen in the body 6 may be visually determined.
However, when the centrifuge tube of this invention is to be used both for the collection of a specimen of urine and the initial analysis thereof by heating to qualitatively detect the presence of albumin, for example, the tube must be transparent in order to clearly observe any changes in clarity of the specimen as it is heated.
Here, the centrifuge tube and its contained specimen may be immersed in a water bath, generally indicated 13 (see FIG. 4), to heat the specimen for such purpose before any centrifuging or subsequent testing procedures are effected. The plastic from which the centrifuge tube is formed is sufficiently resistant to deformation by heat that it will readily withstand the heat of the water bath at least for the time required to effect such a visually observablequ'alitative test.
As a practical matter, these centrifuge tubes now are always to be transparent so that they may be used for all of the above described types of end uses without having to specially prepare transparent tubes for the collection and analysis of urine specimens.
Although the centrifuge tube of this invention thus far has been described as particularly useful in diagnostic procedures such as the PAP test and urinanalysis, it will be appreciated that it also has utility in other types of laboratory procedures. For example, vortex mixing, as distinguished from centrifuging, is frequently required. In such mixing operation the container is revolved about its longitudinal axis at a speed sufficient to create a vortex. The centrifuge tube of this invention would enhance such a mixing operation due to the helical structure of the body 6, particularly where the direction of rotation is repeatedly reversed.
1. In a method of employing a single device for the collecting, centrifuging and the qualitative heat analyzing of a solids-containing liquid specimen obtained from a living being, the steps of; supplying a molded centrifuge tube formed from a type of plastic that is transparent upon completion of molding, that remains transparent upon exposure to moderate heat and that includes a body shaped as a bellows-folded plural-coil helix having a closed bottom including a penetrable membrane and a top provided with an axially extending hollow tip in open communication with the interior of said body; employing said centrifuge tube as a syringe for the collection of said solids-containing liquid specimen; subjecting said tube and its contained specimen to centrifuging whereby to concentrate the solids of said specimen adjacent said penetrable membrane at the bottom of said tube; then subjecting said tube and the centrifuged contents thereof to sufficient heat to cause a change in the condition of the said centrifuged contents as may be qualitatively determined by visual observation; then penetrating the bottom membrane of said centrifuge tube with a hollow needle; leaving said hollow needle in place; and then employing said centrifuge tube as a positive acting syringe to discharge at least part of the centrifuged contents thereof onto a receiver for subsequent analytical processing.