Apparatus, system and method for filtering liquid samples

Abstract

An apparatus and a system for filtering a liquid sample in a sample well (310) by transferring the liquid out of the sample well (310) through a filter member (320) situated at a bottom part of the sample well (310). The apparatus and the system include a syringe (100), and a seal member (200) arranged around a nozzle (140) of the syringe (100) in such a way that the syringe (100) is adjustable in connection with an upper part of the sample well (310) in a substantially airtight manner. A method for filtering a liquid sample and use of the system for filtering eluted blood are also disclosed.

Claims

1. A system for filtering liquid samples, the system comprising: a sample plate comprising a plurality of sample wells configured to hold the liquid samples, each of the sample wells having a filter member at a bottom part thereof; an array of syringes connectable to the plurality of the sample wells so that one syringe gets connected to one sample well, each of the syringes comprising a cylinder, a piston movable within the cylinder and connected to an end of a rod, and a seal member disposed around a nozzle of the syringe so that the seal member is in direct contact with an outer surface of a bottom portion of the nozzle, the seal member being configured to provide an airtight connection between the syringe and an upper part of a respective sample well of the sample plate by the seal member engaging with an upper part of a respective sample well such that the syringe is adjustable in connection with the upper part of the respective sample well of the sample plate in a substantially airtight manner; and a control unit configured to control the operation of the syringes by controlling movement of rods that are connected to the pistons of the respective syringes.

2. The system according to claim 1, wherein the control unit is configured to control the operation of the syringes independently.

3. The system according to claim 1, wherein the seal member is movable along an outer surface of the nozzle.

4. The system according to claim 1, wherein the seal member is detachable from the nozzle.

5. The system according to claim 1, wherein the seal member is a hollow cylinder.

6. The system according to claim 1, wherein the end of the seal member contacting the upper part of the sample well is bevelled.

7. A method for filtering liquid samples in a plurality of sample wells, each of the sample wells having a filter member at a bottom part thereof, the method comprising: aspirating air into syringes of an array of syringes, each of the syringes comprising a cylinder and a piston movable within the cylinder and connected to an end of a rod; adjusting the syringes in connection with upper parts of the sample wells in a substantially airtight manner so that one syringe is connected to one sample well and an airtight connection between the syringe and an upper part of the respective sample well is provided by a seal member disposed around a nozzle of the syringe engaging with the upper part of the respective sample well so that the seal member is in direct contact with an outer surface of a bottom portion of the nozzle; and dispensing air from the syringes into the sample wells, such that portions of the liquid samples are transferred out of the sample wells through the filter members, wherein the air is aspirated into the syringes and dispensed from the syringes by moving rods that are connected to the pistons of the respective syringes.

8. The method according to claim 7, further comprising directing the filtered portions of the liquid samples in other sample wells.

9. The method according to claim 7, further comprising aspirating air from the sample wells into the syringes, such that the liquid is drawn through the filter members into the sample wells due to underpressure.

10. The method according to claim 7, wherein the liquid samples to be filtered comprise eluted blood.

11. The system according to claim 3, wherein the seal member is detachable from the nozzle.

12. The system according to claim 1, wherein an outer circumferential portion of the seal member engages with an inner circumferential portion of the upper part of the respective sample well when the seal member engages with the upper part of the respective sample well.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

(2) FIGS. 1A-1D illustrate the procedure of filtering a liquid sample by using an apparatus according to an embodiment of the invention,

(3) FIG. 2 illustrates a system according to an embodiment of the invention, and

(4) FIG. 3 illustrates a system according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) FIGS. 1A-1D illustrate the procedure of filtering a liquid sample by using an apparatus according to an embodiment of the invention.

(6) The apparatus for filtering the liquid sample comprises a syringe 100. The syringe 100 comprises a cylinder 110 for holding a measured volume of air, a piston 120 arranged in a movable manner within the cylinder 110, a rod 130 connected to the piston 120, and a nozzle 140 through which air can be aspirated and dispensed.

(7) The apparatus also comprises a seal member 200 arranged around the nozzle 140 of the syringe 100. The seal member 200, which is manufactured from an elastic material, is arranged to be movable along an outer surface of the nozzle 140 so that the distance between the tip of the syringe 100 and a bottom of a first sample well 310 can be varied when the syringe 100 is in connection with an upper part of the first sample well 310 in a substantially airtight manner.

(8) The liquid sample contained in the first sample well 310 has been processed to precipitate desired components of the sample. The first sample well 310 comprises a filter member 320 situated at the bottom part of the sample well 310. The filter member 320 is used for separating the precipitated components from the liquid when the liquid is being transferred through the filter member 320. A second sample well 410 has been arranged underneath the first sample well 310 in order to collect the filtrate, i.e. the liquid.

(9) The first step of the filtering procedure is shown in FIG. 1A, wherein air is aspirated into the cylinder 110 by moving the rod 130. At this stage, the syringe 100 is not in contact with the first sample well 310. Next, as is shown in FIG. 1B, the syringe 100 is adjusted in connection with the upper part of the first sample well 310 in a substantially airtight manner.

(10) Then, as is shown in FIG. 1C, air is dispensed from the syringe 100 into the first sample well 310. The dispensed air generates overpressure, which forces the liquid through the filter member 320. The portion of the liquid being transferred through the filter member 320 is directed in the second sample well 410.

(11) After a desired amount of the liquid sample has been filtered, underpressure is generated by aspirating air into the syringe 100, while still keeping the syringe 100 in connection with the upper part of the first sample well 310 in a substantially airtight manner. Consequently, liquid drops hanging from the filter member 320 are drawn into the first sample well 310.

(12) In the last step of the procedure, as is shown in FIG. 1D, the syringe 100 is moved away from contact with the first sample well 310.

(13) FIG. 2 illustrates a system according to an embodiment of the invention for filtering several liquid samples. The system comprises a first sample plate 300 having a plurality of first sample wells 310 for holding the liquid samples prior to filtering. Each of the first sample wells 310 has a filter member 320 at a bottom part.

(14) The system also comprises an array of syringes 100. Each of the syringes 100 comprises a seal member 200 arranged around a nozzle 140 of the syringe 100. The syringes 100 are adjusted in connection with upper parts of the first sample wells 310 of the first sample plate 300 in a substantially airtight manner.

(15) The system also comprises a control unit 500 for controlling the movement of rods 130. The rods 130, which are connected to pistons 120, are moved in a vertical direction either simultaneously or independently.

(16) Underneath the first sample plate 300, there is a second sample plate 400 having a plurality of second sample wells 410. The first sample plate 300 and the second sample plate 400 are disposed in a stacked relationship such that the first sample wells 310 are aligned with the second sample wells 410.

(17) Another example of a system according to the invention is shown in FIG. 3. In FIG. 3, there is illustrated a first actuator 510 which is used for moving a rod 130 of the syringe 100 in order to aspirate air into the cylinder 110 and dispense air out of the cylinder 110. A second actuator 520 is adapted for moving the syringe 100 in a vertical direction, relative to a first sample plate 300 and a second sample plate 400. The sample plates 300, 400 are arranged to be movable in a horizontal direction in order to position each sample well 310, 410 underneath the syringe 100.

(18) Only advantageous exemplary embodiments of the invention are described in the figures. It is clear to a person skilled in the art that the invention is not restricted only to the examples presented above, but the invention may vary within the limits of the claims presented hereafter. Some possible embodiments of the invention are described in the dependent claims, and they are not to be considered to restrict the scope of protection of the invention as such.