WO2000054019A1

WO2000054019A1 - Device for sampling liquids

Info

Publication number: WO2000054019A1
Application number: PCT/AU2000/000182
Authority: WO
Inventors: Warren Ward; Rosemary Sutton
Original assignee: Commonwealth Scientific And Industrial Research Organisation; Australian Wool Research & Promotion Organisation
Priority date: 1999-03-10
Filing date: 2000-03-10
Publication date: 2000-09-14
Also published as: ZA200107453B; NZ514032A; GB2363198B; GB2363198A; GB0121843D0

Abstract

The specification discloses a device for sampling liquids, especially blood. The device includes a first side (1), a second side (2) secured to the first side at a corresponding end of each side, and a piece of absorbent material (3) secured between each side. The first and second sides have fold lines (5) adjacent to the corresponding end of each side so that each may be folded back to an open position to form a handle and expose the absorbent material. The device may then be returned to a closed position in which the absorbent material is substantially enclosed by the first and second sides.

Description

DEVICE FOR SAMPLING LIQUIDS

The present invention relates to a device for sampling liquids for subsequent testing. In particular, it relates to a device for sampling liquids such as solutions, suspensions and slurries, in which a solid is dispersed in a liquid. The invention has particular relevance to the collection of blood samples for subsequent testing.

The conventional method for DNA pedigreeing of sheep consists of taking a 5 to 10 ml blood sample from the jugular vein of a sheep using a vacutainer. A vacutainer is a needle attached to a syringe and a vacuum tube. It is a device that requires experience in its use. Normally a veterinary surgeon is required to take a blood sample with a vacutainer. Furthermore, conventional extraction of DNA from whole blood requires expensive reagents and several centrifugation and transfer steps which may take 10 hours of labour over a 3 day period in order to process 100 samples. The conventional extraction technique involves a number of transfer steps, inherently involving the risk of sample mix up.

An object of the present invention is to provide a simple method of collecting a sample that can be used in a PCR thermal cycler. Accordingly, the present invention provides a device for sampling a liquid for subsequent testing, the device including a first side, a second side secured to the first side at a corresponding end of each side, and a piece of absorbent material secured between each side, the first and second sides having fold lines adjacent to the corresponding end of each side so that each side may be folded back to an open position to form a handle and expose the absorbent material, and returned to a closed position in which the absorbent material is substantially enclosed by the first and second sides. Preferably, the absorbent material is paper of a type similar to that known as blotting paper. Any other inert absorbent material may also be used.

Each side may be formed from a flat sheet of material, such as cardboard. The first side may be secured to the second side by means of a staple, in which case the absorbent material may also be secured between the two sides by means of the staple.

Preferably, the absorbent material includes one or more tips that are so shaped that they are capable of fitting neatly within a PCR tube, thereby maximising the surface area exposed to elution by a suitable solvent.

Either the first or second side may be provided with securing means so that the free end of one can be secured to the free end of the other when the device is in the closed position. The securing means may comprise a partially cut out tab which can be folded back by elastic deformation so that it returns to its original position and secures the free end of the side to which it is not attached.

A preferred embodiment of the invention is described with reference to Figures 1 and 2, in which Figure 1 is a perspective view of a device according to the invention, depicting it in a partially open position, and Figure 2 is a perspective view of the device in the closed position.

Figure 1 depicts a sampling device comprising a first side 1 and a second side 2 having a piece of absorbent material 3 secured therebetween by means of a staple 4. The two sides 1 and 2 are formed integrally from a sheet of cardboard. The cardboard has been provided with fold lines on sides 1 and 2, one of which 5 is shown in Figures 1 and 2. The absorbent material has an exposed end comprising one or more tips 6 that are so shaped that when cut off at the base thereof, they fit tip-first, neatly into a PCR tube. Side 2 is provided with a triangular tab 7, two sides of which are cut out and the remaining side 8 of which remains attached to and integral with side 2.

In use, side 1 and side 2 are folded back by rotating them about fold lines 5 to a fully open position in which sides 1 and 2 are parallel to each other, and can be held as a handle and the tips 6 of the absorbent material 3 are fully exposed. Whilst held in the open position by the handle formed by sides 1 and 2, a blood sample can be taken by squeezing the ear of the animal to be tested, nicking the ear with a lancet and absorbing blood into the tips 6 of the absorbent material 3. Having taken a sample, the sides 1 and 2 may be returned to the closed position by rotating them back to that position about fold lines 5. Once in the closed position, the tab 7 can be exposed and its tip allowed to elastically close back over the free end 9 of side 1.

The name or some other means of identification of the animal may be written on the card, and the card placed in an airtight container with other samples and desiccant and sent to a laboratory for testing.

In the laboratory the device is opened and the tips 6 cut off and placed tip-first into the next available well of a standard 96 well tray of PCR tubes. The animal identification is recorded on a computer (or manual sheet) against the position coordinates and tray number for sample tracking. The absorbent tips 6 placed in each tube can be efficiently washed and DNA extracted.

The process steps involved in pedigreeing involve transferring eluted samples to a second type of 96 well tray, but the sample coordinates can be preserved and a multi-channel pipette or robot-operated pipette can be used to minimise sample mix up. Normally sufficient DNA is extracted from one tip to pedigree an animal for 15 polymorphic markers.

Clearly the sampling device has many other applications, including anonymous testing for antibodies associated with the virus that produces human immune deficiency. It can be used also for blood enzyme tests which are not affected by drying the blood. For example, the three enzyme assays for genetic disease carried out on blood dried on to Guthrie cards taken from most newborn babies born in hospitals in Australia. The device has many other applications, including testing for blood-borne antibodies or host or foreign DNA, associated with disease in animals or humans.

Claims

CLAIMS ;

1. A device for sampling a liquid for subsequent testing, the device including a first side, a second side secured to the first side at a corresponding end of each side, and a piece of absorbent material secured between each side, the first and second sides having fold lines adjacent to the corresponding end of each side so that each may be folded back to an open position to form a handle and expose the absorbent material and returned to a closed position in which the absorbent material is substantially enclosed by the first and second sides.

2. A device according to claim 1 wherein the absorbent material is paper.

3. A device according to claim 1 or claim 2 wherein the first and second sides are integrally formed from a sheet of cardboard.

4. A device according to any one of the preceding claims wherein each side has a free end opposite to its corresponding end and one side has a securing means so that the free end of one side can be secured to the free end of the other side when the first and second sides are in the closed position.

5. A device according to any one of the preceding claims wherein the absorbent material includes one or more tips that are so shaped that they are capable of fitting neatly within a PCR tube.

6. A device according to any one of the preceding claims wherein the first side is secured to the second side by means of a staple.

7. A device according to claim 6 wherein the piece of absorbent material is secured between the first and second sides by means of the staple.

8. A device according to claim 4 wherein the securing means comprises a partially cut out tab which can be folded back by elastic deformation so that it returns to its original position and secures the free end of the side to which it is not attached.