WO1991016979A2

WO1991016979A2 - Laboratory washing device with swirling current

Info

Publication number: WO1991016979A2
Application number: PCT/US1991/003190
Authority: WO
Inventors: John R. Wells
Original assignee: Source Scientific Systems, Inc.
Priority date: 1990-05-08
Filing date: 1991-05-08
Publication date: 1991-11-14
Also published as: US5325609A; WO1991016979A3; EP0482165A1

Abstract

A liquid handling apparatus is employed for washing the sidewalls of various laboratory vessels. The apparatus is particularly useful for washing the sidewalls of coated microtiter plate wells and for washing magnetic particles which are drawn to the sidewalls of a laboratory vessel having a side pull magnet. The apparatus includes a probe (5) having an inlet (6) and an outlet (7). The inlet aspirates liquid (2) from the laboratory vessel (1). The outlet (7) expresses liquid into the laboratory vessel (1). More particularly, the outlet is bent so as to direct the wash current against the sidewall (3) of the well (1) so as to create a swirling current of wash liquid (2) upon such sidewall (3). In the case of the magnetic particles, the bent outlet (7) serves to express wash liquid (2) with sufficient force so as to dislodge the magnetic particles (10), from the sidewall (3) of the laboratory vessel (1).

Description

TITLE: LABORATORY WASHING DEVICE WITH SWIRLING CURRENT

SPECIFICATION Background The invention relates to devices for washing the sidewalls of laboratory vessels. More particularly, there are two areas of special application for the invention.. In the first area of special application, the invention is employed for washing the sidewalls of coated microtiter plate wells or other similar xauoratory vessels. In the second area, the invention is employed for washing magnetic particles which magnetically adhere to the sidewalls of laboratory vessels having a magnetic side pull.

Many homogenous immunoassays employ a separation and wash step in which bound components are separated from unbound components. If the immunoassay is performed in a coated microtiter plate, the separation step may entail the aspiration of the liquid phase from each well within the microtiter plate. Similarly, if the immunoassay employs coated magnetic particles which are drawn to the sidewall of the laboratory vessel by a side pull magnet, the separation step may entail the drainage of the liquid phase from the laboratory vessel. Since the aspiration or drainage may be incomplete in either event, the separation step may be followed by a wash step so as to remove residual unbound components from the solid phase. In the case of the magnet particles, after the drainage step, the side pull magnet may be temporarily removed from the side of the laboratory vessel so as to allow the magnetic particles to disperse within the wash liquid during the wash step.

A manifold type device for washing coated microtiter plate wells is disclosed by Namba et al., U.S. Patent No. 4,635,665, incorporated herein by reference. Namba's device includes an array of paired concentric pipes for both aspirating and expressing liquids. Each pair of concentric pipes includes one pipe for aspirating liquid and an other pipe for dispensing liquid. The aspirating pipe is attached to a vacuum manifold; the dispensing pipe is attached to a liquid manifold. The concentric pipes are arrayed so as to be alignable with an array of microtiter plate wells. Naraba's device may be employed for simultaneously evacuating liquid from an entire array of microtiter plate wells by immersing the array of concentric pipes within the liquid phase of the array of microtiter wells and then activating the vacuum manifold. Similarly, Namba's device may be employed for simultaneously expressing liquid into the same entire array of microtiter plate wells, by activating the liquid manifold. When liquid is expressed from Naraba's device, it is directed toward the bottom of the well. Since, coated microtiter plate wells may be coated both on the sidewalls and on the bottom, it is desirable to wash both regions as thoroughly as possible. Accordingly, what was sought was a device which could direct the expression of a current of wash liquid onto the sidewalls of coated microtiter plate wells and impart a swirling motion to such current.

Simularly, if the magnetic particles have been drawn to the sidewall of the laboratory vessel due to the influence of the side pull magnet, it would be desirable to dislodge such particles from the sidewall without removing the side pull magnet. Accordingly, what was sought was a device which could direct the expression of a current of wash liquid onto the sidewalls of the laboratory vessel so as to dislodge the magnetic particles therefrom even in the presence of the side pull magnet. Summary The invention is a liquid handling probe for washing the sidewall of various laboratory vessels or for dislodging and washing particles attached thereto. The invention is particularly useful for washing the ssxuewalls of coated microtiter plate wells and for dislodging and washing magnetic particles attached to the sidewall of laboratory vessels having a side pull magnet. However, the invention may be employed in other simular applications.

Each probe includes both a vacuum channel and a liquid channel. The vacuum channel is employed for aspirating liquid from the well or vessel. The liquid channel is employed for expressing liquid into the well or vessel.

The outlets of the liquid channels are bent at an angle so as to direct wash liquid against the sidewall of the well. In the case of the coated microtiter plate well, the bent outlets impart a rotational momentum to the expressed wash liquid so that the wash liquid may swirl after it is expressed into the well. After striking the sidewall, the liquid swirls and follows a spiral path down the sidewall to the bottom of the well. In the case of the laboratory vessel having a side pull magnet, the bent outlets are positioned opposite the magnetic particles which adhere to the sidewall of the vessel. The expression of wash liquid with force onto the adhering magnetic particles causes such magnetic particles to become dislodged from the sidewall.

In the preferred mode, the vacuum channel is aligned with the center of the microtiter plate well and the liquid channels are displaced from the center. In an alternative embodiment, the outlets of the liquid channels may be directed so that they include a non-radial component so as to enhance the resultant swirling motion of the wash liquid within the laboratory vessel. In another alternative embodiment, a plurality of probes may be connected to a vacuum manifold and a liquid manifold respectively so that several wells may be washed simultaneously. Furthermore, the probes may be manipulated by a programable X-Y-Z positioner so as to automate their movement.

Brief Description of the Drawings Fig. 1 is a sectional view of a microtiter plate well and a fragment of a probe therein.

Fig. 2 (a) is a plan view of the well of the microtiter plate and probe of Fig. 1 viewed from above. Fig. 2 (b) is the same as Fig. 2 (a) except that it illustrates the expression of liquid and the resultant swirling motion of the wash liquid (indicated by arrows) within the well of the microtiter plate.

Fig. 3 (a) is a plan view of the well of the microtiter plate and of an alternative embodiment of the probe illustrating an alternative configuration for the bent outlet.

Fig. 3 (b) is the same as Fig. 3 (a) except that it illustrates the expression of liquid and the swirling motion of the wash liquid within the well of the microtiter plate which results from the use of the bent outlet illustrated in Fig. 3 (a).

Fig. 4 (a) is a plan view of a laboratory vessel having magnetic particles drawn to the sidewall of the vessel under the influence of a side pull magnet illustrating a probe with an outlet having a radial configuration.

Fig. 4 (b) is the same as Fig. 4 (a) except that it illustrates the expression of liquid and the resultant dislodging of the magnetic particles from the sidewall of the laboratory vessel. Fig. 5 (a) is a plan view of a laboratory vessel similar to the laboratory vessel of Fig. 4 (a) illustrating a probe with an outlet having an off-radial configuration similar to the probe of Fig. 3 (a). Fig. 5 (b) is the same as Fig. 5 (a) except that it nxustrates the expression of liquid and the resultant dislodging of the magnetic particles from the sidewall of the laboratory vessel due to the off-radial force of the expressed wash liquiu. Fig.'s 6 - 11 are sectional views of the test tube (laboratory vessel) and probe of Fig. 4(a) illustrating the sequence for washing magnetic particles which are attached to a sidewall of a laboratory vessel having a side pull magnet. Fig. 6 illustrates the test tube filled with prewash liquid and having two pellets of magnetic particles attached to the side wall of the test tube by means of the side pull magnets.

Fig. 7 illustrates the prewash liquid being aspirated as the probe is lowered into the test tube.

Fig. 8 illustrates the completion of the aspiration step.

Fig. 9 illustrates the elevating of the probe within the test tube, the expression of wash liquid toward the sidewall of the test tube and the commencement of the dislodging of the pellets of magnetic particles attached thereto.

Fig. 10 illustrates the continuation of the addition of wash liquid to the test tube and the elevating of the probe therein for avoiding contact between the probe and the wash liquid within the test tube.

Fig. 11 illustrates the completion of the resuspension of the magnetic particles within the wash liquid. Fig. 12 is perspective as an apparatus which includes an assembly of probes of the type illustrated in Fig. 1, the vacuum channel of each probe being attached to a vacuum manifold and vacuum source, the liquid channel of each probe being attached to a liquid manifold and liquid source.

Fig. 13 is a sectional view of Fig. 11 illustrating the attachment of the probes to the apparatus.

Fig. 14 is an alternative sectional view of Fig. 11 illustrating another view of the attachment of the probes to the apparatus.

DETAILED DESCRIPTION OF THE INVENTION Apparatus for Washing the Sidewalls of Coated Microtiter Plate Wells

Many coated microtiter plate wells (1) are coated both on the bottom and on the sidewalls. Accordingly, an efficient washing of such a coated microtiter plate well (1) may be facilitated by directing the flow of wash liquid (2) firstly onto the sidewalls (3) and then allowing the wash liquid (2) to flow to the bottom (4) of the well (1). Since liquid (2) flows naturally onto the bottom (4), the more difficult task is the directing of the wash liquid onto the sidewalls (1) of the well. The invention employs a liquid handling apparatus having a probe (5) with an inlet (6) for aspirating liquid (2) from the bottom (4) of the wells (1) and a bent outlet (7) for directing the expression of wash liquid (2) onto the sidewalls (3). In the preferred embodiment, the outlet (7) is positioned within the well (1) so as to cause wash liquid (2) to swirl upon the sidewall (3) before spiraling down to the bottom (4).

The probe (5) includes both a liquid channel (8) and a vacuum channel (9). In the preferred embodiment, the liquid channel (8) and vacuum channel (9) are parallel or adjacent to one another and are mechanically coupled to one another. Accordingly the movement of the two channels is coupled, i.e. the two channels move in unison with one another. In the preferred mode, both the liquid channel (8) and the vacuum channel (9) have a cylindrical shape and a composition of metal, high strength plastic, or similar materials.

The vacuum channel (9) terminates with an inlet (6). When the probe (5) is inserted into the well, the inlet (6) is positioned adjacent to the bottom (4) of the well (1). This position next to the bottom (4) of the well, allows the inlet (6) to effectively evacuate liquid (2) from the well ÷ •

The liquid channel (8) terminates with one or more outlets (7). The outlet (7) is bent with respect to the inlet (6). Accordingly, when the probe (5) is positioned with the inlet (6) adjacent to the bottom (4) of the well, the outlet (7) is positioned for expressing wash liquid (2) onto the sidewalls (3). In the preferred embodiment, the liquid channel (8) is terminated with two or more outlets (7). The bent outlets (7) may branch from the end of a single liquid channel (8). Alternatively, the liquid channel (8) may include two or more subchannels, with each of the subchannels terminating with an outlet (7). In any event, each outlet (7) is bent with respect to the inlet (6) so as to direct the expression of wash liquid (2) onto the sidewalls (3) of the coated well or vessel (1). More importantly however, the outlets (7) have a configuration, which, in combination with one another, imparts a net angular momentum to the wash liquid (2) as it is expressed from the probe (5).

A preferred embodiment for the probe (5) is illustrated in Fig.'s 1-3. This preferred embodiment allows the probe (5) to impart an angular momentum to the expressed wash liquid (2) independently of its position within the microtiter plate well (1). However, even with this preferred embodiment, it is preferred to center the probe (5) within the well (1). In this preferred embodiment, the liquid channels (8) are positioned adjacent to a central vacuum channel (9) and the vacuum channel (9) is aligned with the axis of the microtiter plate well (1). The inlet (6) faces the bottom (4) of the well (1). The bent outlets (7) face the sidewalls (3), i.e. the outlets (7) are oriented so that the expressed liquid (2) is directed against the sidewalls (3). Because of the configuration of the outlets (7) of this preferred embodiment, the liquid (2) expressed from this embodiment will impact the sidewalls (3) with a non-radial component even if the probe (5) is not centered on the axis of the well (1).

Nevertheless, it is preferred to optimize the swirling motion of the liquid by aligning the probe with the axis of the well.

In an other embodiment, the liquid channel (8) has only one outlet (7). The embodiment is entirely dependent upon the orientation within the well (1) for the creation of a swirling current of wash liquid (3) upon the sidewall (3) of the well (1). Hence, it is necesssary with respect to this embodiment to take care to position the bent outlet (7) within the wells (1) so that the liquid (2) expressed therefrom strikes the sidewall (3) with at least a partial non-radial component.

In the preferred embodiment, a plurality of probes (5) of the type described above are employed with a manifold type liquid (2) handling apparatus similar to the apparatus described by Namba et al , U.S. Patent No. 4,635,665, incorporated herein by reference. The apparatus includes two manifolds, viz. a dispensing manifold and an aspirating manifold. The dispensing manifold is connected to a liquid (2) source for charging the dispensing manifold with liquid (2). The aspirating manifold is connected to a vacuum source for evacuating the aspirating manifold. Connected to the dispensing manifold is a plurality of liquid channels (8). Activation of the liquid (2) source first causes the charging of the dispensing manifold then causes the expression of liquid (2) from each of the outlets (7) of the plurality of liquid channels (8). Connected to the aspirating manifold is a plurality of vacuum channels (9). Activation of the vacuum source first causes the evacuation of the aspirating manifold then causes the aspiration of liquid (2) into each of the inlets (6) of the plurality of vacuum channels (9). In the preferred mode, each of the various channels are siphone shaped and attach to the top nf their respective manifolds.

The plurality of probes (5) emanating from the manifolds is organized into an array which matches or complements the geometry of the array of microtiter plate veils (1) or similar vessels. Accordingly, thp array of probes (5) may be inserted into the array of wells (1) with one motion.

The apparatus may also include an X-Y-Z positioner or other vertical and/or horizontal translating means for vertically and/or horizontally translating the array of probes (5). Horizontal translation may be employed for washing a series of rows of microtiter plate wells (1). Vertical translation of the probes (5) is employed during the washing method. Method for Washing the Sidewalls of Coated Microtiter Plate Wells The method for washing the sidewalls of a coated microtiter plate well involves three steps, viz.:

1. Aspirating or evacuating prewash liquid (2) from the microtiter plate well;

2. Expressing wash liquid (2) into the well, and then 3. Aspirating or evacuating the resultant wash liquid (2) from the well. Prewash liquid (2) is aspirated or evacuated from the microtiter plate wells (1) by activating the vacuum source and translating the probe (5) vertically downward into the wells (1) until the inlet (6) of the probe (5) is adjacent to the bottom (4). The prewash liquid (2) is aspirated from the wells (1) through an inlet (6) within the probe (5). Wash liquid (2) is then added to the well (1). Wash liquid (2) is added by activating the liquid source and expressing wash liquid from the outlet (7) of the liquid channel (8) onto the sidewalls of the coated vessel. In a preferred mode, the probe (5) may be translated so as to avoid contact between the outlets (7) and the wash liquid (2) within the wells (1) and so as to wash the sidewall (3) progressively further up from the bottom (4). In a preferred mode, the expression of wash liquid (2) onto the sidewalls (3) of the wells (1) through the outlet (7) imparts a swirling motion to the wash liquid (2) upon the sidewalls (3).

The above washing cycle may be repeated as often as desired.

Apparatus for Washing the Magnetic Particles Adhering to the Sidewall of a Laboratory

Vessel Having a Side Pull Magnet The principles and design which underlie the apparatus for washing the sidewalls of a coated microtiter plate well (1) are substantially identical to the principles and design which underlie the apparatus for washing the sidewalls of a laboratory vessel (1) to which magnetic particles (10) are attached by means of a side pull magnet (11). In each case pre-wash liquid is first drawn from the bottom of the vessel (1) and then wash liquid (2) is expressed onto the sidewall (3) of the vessel (1). However, the design and dimensions of - li ¬ the apparatus may be adapted to the design and dimensions of the particular vessel (1) and to the placement of the side pull magnet (11) with respect to such vessel (1). Also, the force with which wash liquid must be expressed onto the sidewalls (3) of a vessel (1) in order to dislodge magnetic particles (10) therefrom will depend upon several factors, e.g. the strength and placement of the side pull magnet (11) and the size and magnetic strength of the magnetic particles (10).

Method for Washing the Magnetic Particles Adhering to the Sidewall of a Laboratory Vessel Having a Side Pull Magnet The apparatus and probes (5) described above may be employed within a method for washing magnetic particles (10) which have been drawn to the sidewall (3) of a - laboratory vessel (1) and which are magnetically attached thereto by means of a side pull magnet (11). The method for washin-g the sidewalls of coated microtiter plate wells (1) is substantially identical to the method for washing the magnetic particles (10) which are magnetically attached to the sidewall of a laboratory vessel (1) having a side pull magnet (11).

Conventionally, magnetic particles (10) are employed for separating a bindable component from unbound components. A suspension of magnetic particles (10) is incubated with the bindable component. The suspension is then magnetically pelleted to the sidewall (3) of the laboratory vessel (1). The unbound components remain within the prewash liquid and require removal from the pelleted magnetic particles (10).

Accordingly, after the magnetic particles (10) have been drawn to the sidewall (3), the prewash liquid may be removed by application of the probe (5). The probe (5) is initially inserted into the top of test tube (1). The probe (5) is then translated vertically downward into the vessel (1) while simultaneously activating the vacuum source. Activation of the vacuum source causes prewash liquid to be aspirated into the vacuum channel (9) as the probe (5) is translated downward. In the preferred mode, the rate of aspiration is sufficiently great so that the inlet (6) of the vacuum channel (9) remains near the meniscus of the prewash liquid as both the meniscus and the probe (5) descend within the tube.

The vertically downward translation of the probe (5) terminates when the inlet (6) of the vacuum channel (9) contacts the bottom (4) the test tube (1).

After the prewash liquid has been evacuated from the test tube (1) as indicated above, the probe (5) may be elevated so that the outlets (7) of the liquid channel (8) are opposite the pellet of magnetic particles (10) which remains adhering to the sidewall (3) of the test tube (1). The magnetic particles (10) may be dislodged from the sidewall (3) of the test tube (1) by directing the expression of wash liquid (2) with force onto central region of such sidewall (3) pellet. Dislodging the magnetic particles (10) from the sidewall (3) causes them to become resuspended within the wash liquid (2). In the preferred mode, the wash liquid (2) contains a low level of surfactant.

It is important not to contaminate the outlet (7) with prewash liquid or with magnetic particles (10) as this could lead to cross comtamination if the probe (5) is employed with other test tubes (1). As wash liquid (2) is expressed into the test tube (1), the probe (5) is translated vertically upward. The vertically upward translation of the probe (5) proceeds at a speed which allows the inlet (6) and outlet (7) to remain above the rising surface level of the wash liquid (2) within the test tube (1). The optimal quantity of wash liquid (2) to be expressed into the test tube (1) will depend upon the particular application.

Expression of wash liquid (2) with force onto the pellet can create foam, particularly if the wash liquid (2) includes surfactant. The presence of this foam can impede the subsequent magnetic separtion of the magnetic particles (10). The wash liquid (2) may be defoamed by drawing air through the test tube (1). One method to do this is to draw air through the forked inlet (6)s. This air circulation causes the liquid to defoam and allows the magnetic sedimentation to proceed at its usually rate.

Since the test tube (1) remains mounted within its magnetic rack throughout this procedure, the resuspended magnetic particles (10) will begin to be magnetically drawn to the sidewall (3) of the test tube (1) as soon as the mixing of the suspension is stopped by terminating the expression of wash liquid (2) into the test tube (1) .

After the magnetic separation has occurred and the magnetic particles (10) have been drawn once again to the sidewall (3) of the test tube (1), the wash liquid (2) may again be evacuated from the test tube (1). As before, the probe (5) is lowered into the test tube (1) while vacuum source is activated so as to cause the wash

liquid (2) to be aspirated into the inlet (6)s of the vacuum channel (9). The aspiration of the wash liquid (2) may be performed in the same manner as the aspiration of the prewash liquid.

The above washing protocol may be repeated as often as desired.

Furthermore, both methods may employ a plurality or array of probes (5) each of which may be attached to a vacuum manifold (12) and to a wash liquid manifold (13) for simultaneously washing several vessels (1) at once. Additioanll , the apparatus may include an X-Y-Z positioner or other vertical and/or horizontal translating means for vertically and/or horizontally translating the array of probes (5).

Claims

What is claimed is:

1. A probe (5) employed in conjunction with an apparatus for washing a coated vessel (1) with wash liquid (2), the coated vessel (1) having a bottom (4) and sidewalls (3) and containing a pre-wash liquid, the probe (5) comprising: a liquid channel (8) terminating with an outlet (7) for expressing wash liquid (2) into the coated vessel (1), and a vacuum channel (9) terminating with an inlet (6) for aspirating liquids from the coated vessel (1), said liquid channel (8) and said vacuum channel (9) being adjacent to one another and coupled to one another with respect to movement, said inlet (6) being positionable adjacent to the bottom (4) of the coated vessel (1) for aspirating liquids therefrom, said outlet (7) being bent with respect to said inlet (6) for directing the expression of wash liquid (2) onto the sidewalls (3) of the coated vessel (1).

2. A probe (5) as described in claim 1 for washing a coated vessel (1) having a circular sidewall (3), wherein: said vacuum channel (9) being alignable with the axis of the circular sidewall (3) of the coated vessel (1), and said outlet (7) having an orientation, when said vacuum channel (9) is aligned with the axis of the circular sidewall (3), for expressing wash liquid (2) onto the circular sidewall (3) of the coated vessel (1) with a direction which is at least partially non-radial with respect to the circular sidewall (3).

3. A probe (5) employed in conjunction with an apparatus for washing a coated vessel (1) with wash liquid (2), the coated vessel (1) having a bottom (4) and sidewalls (3) and containing a pre-wash liquid, the probe (5) compris u_B. a liquid channel (8) terminating with two or more outlets (7) for expressing wash liquid (2) into the coated vessel (1), and a vacuum channel (9) terminating with an inlet (6) for aspirating liquids from the coated vessel (1), said liquid channel (8) and said vacuum channel (9) being adjacent to one another and coupled to one another with respect to movement, said inlet (6) being positionable adjacent to the bottom (4) of the coated vessel (1) for aspirating liquids therefrom, each of said outlets (7) being bent with respect to said inlet (6) for directing the expression of wash liquid (2) onto the sidewalls (3) of the coated vessel9 (1) and having a configuration for imparting angular momentum to the wash liquid (2) as the wash liquid (2) strikes the sidewalls (3) of the coated vessel (1), whereby the sidewalls of the coated vessel (1) may be washed by expressing wash liquid (2) onto the sidewalls (3) of the cated vessel (1) and swirling the wash liquid (2) thereon by means of said outlet (7).

4. A probe (5) as described in claim 3 wherein: said liquid channel (8) including two or more subchannels, each of said subchannels terminating with one of said outlets (7).

5. An apparatus for washing a plurality of coated vessels (1) with wash liquid (2), each of the coated vessels (1) having a bottom (4) and sidewalls (3) and containing a pre-wash liquid, the apparatus comprising: a liquid source for supplying wash liquid (2), a vacuum source for supplying a vacuum, a dispensing manifold connected to said liquid source, an aspirating manifold connected to said vacum SOUl c, a plurality of said liquid channels (8), each of said liquid channels (8) connected to said liquid manifold, and a plurality of said vacuum channels (9), each of said vacuum channels (9) connected to said aspirating manifold, each of said liquid channels (8) terminating with two or more outlets (7) for expressing wash liquid (2) into the coated vessel (1), and each of said vacuum channels (9) terminating with an inlet (6) for aspirating liquids from the coated vessel

(1), each of said liquid channels (8) corresponding to one of said vacuum channels (9), said corresponding liquid channels (8) and vacuum channels (9) bing adjacent to and coupled to one another, each of said inlets (6) being positionable adjacent to the bottom (4) of one of the plurality of coated vessels (1) for aspirating liquids therefrom, each of said outlets (7) being bent with respect to said inlets (6) for directing the expression of wash liquid (2) onto the sidewalls (3) of one of the coated vessels (1) when said inlet (6) is positioned adjacent to the bottom (4) of the coated vessel (1) and having a configuration, in combination with the remaining outlets (7), for imparting angular momentum to the wash liquid (2) as the wash liquid (2) strikes the sidewalls (3) of the coated vessel (1).

6. A method for washing a coated vessel (1) containing pre-wash liquid, the method comprising the following steps:

Step A: translating a probe (5) vertically downward into the coated vessel (1) until the inlet (6) of the probe (5) is adjacent to the bottom (4) of the coated vessel (1); while sinultaneous ;

Step B: aspirating the pre-wash liquid from the coated vessel (1) through an inlet (6) within the probe (5); then

Step C: expressing wash liquid (2) onto the sidewalls (3) of the coated vessel (1) by means of bent outlets (7) extending from the probe (5) and imparting a swirling motion to the wash liquid (2) upon the sidewalls (3) of the coated vessel (1); while simultaneously

Step E: translating the probe (5) vertically upward while expressing wash liquid (2) onto the sidewalls (3) of the coated vessel (1) progressively more distal from the bottom (4).

7. A method for washing a coated vessel (1) as described in claim 6 comprising the following additional steps:

Step F: repeating said Steps A-E as desired for achieving multiple wash cycles.

8. A method for washing a plurality of coated vessels (1), each coated vessel (1) containing pre-wash liquid, the method comprising the following steps:

Step A: translating a plurality of probes (5) vertically downward with each probe (5) corresponding to and descending into one of the plurality of coated vessels (1) until the inlet (6) of each probe (5) is adjacent to the bottom (4) of its corresponding coated vessel (1); while simultaneously Step B: aspirating the pre-wash liquid from each of the coated vessels (1) through inlets (6) within each of the probes (5); then

Step C: expressing wash liquid (2) onto the sidewalls (3) of each of the coated vessels (1) by means of bent outlets (7) extending from each of the probes (5) and imparting a swirling motion to the wash liquid (2) upon the sidewalls (3) and bottom (4) of each of the coated vessels (1); and

Step E: translating the plurality of probes (5) vertically upward for expressing wash liquid (2) onto the sidewalls (3) of each of the coated vessels (1) progressively more distal from the bottom (4).

9. A probe (5) employed in conjunction with an apparatus for washing and dislodging magnetic particles (10) with wash liquid (2), the magnetic particles (10) being magnetically attached to the side wall of a vessel (1), the vessel (1) having a bottom (4) and containing a pre-wash liquid, the probe (5) comprising: a liquid channel (8) terminating with an outlet (7) for expressing wash liquid (2) into the vessel (1), and a vacuum channel (9) terminating with an inlet (6) for aspirating liquids from the vessel (1), said liquid channel (8) and said vacuum channel (9) being adjacent to one another and coupled to one another with respect to movement, said inlet. (6) being positionable adjacent to the bottom (4) of the vessel (1) for aspirating liquids therefrom, said outlet (7) being bent with respect to said inlet (6) for directing the expr_ ssion of wash liquid (2) onto the magnetic particles (10) attached to the sidewall (3) of the vessel (1) for dislodging and washing the magnetic particles.

10. A probe (5) as described in claim 9 for washing magnetic particles (10), wherein the vessel (1) having a circular sidewall (3) and wherein: said vacuum channel (9) being alignable with the axis of the circular sidewall (3) of the vessel (1), and said outlet (7) of said liquid channel ^8) having an orientation, when said vacuum channel (9) is aligned with the axis of the circular sidewall (3), for expressing wash liquid (2) onto the magnetic particles (lϋ) attached to the circular sidewall (3) of the vessel (1) with a direction which is at least partially non-radial with respect to the circular sidewall (3).

11. A probe (5) employed in conjunction with an apparatus for washing and dislodging magnetic particles

(10) with wash liquid (2), the magnetic particles (10) being magnetically attached to the side wall of a vessel (1), the vessel (1) having a bottom (4) and containing a pre-wash liquid, the probe (5) comprising: a liquid channel (8) terminating with two or more outlets (7) for expressing wash liquid (2) into the vessel (1) , and a vacuum channel (9) terminating with an inlet (6) for aspirating liquids from the vessel (1), said liquid channel (f.) and sa">d "a ii' channel (9) being adjacent to one another and coupled to one another with respect to movement, said inlet (6) being positionable adjacent to the bottom (4) of the "essel (1) for aspirating liquids therefrom, each of said outlets (7) being bent with respect to said inlet (6) for directing the expression of wash liquid (2) onto the magnetic particles (10) attached to the sidewalls (3) of the vessel (1) and having a configuration, in combination with the remaining outlets

(7).

12. A probe (5) as described in claim 11 wherein: said liquid channel (8) including two or more subchannels, each of said subchannels terminating with one of said outlets (7).

13. An apparatus for washing magnetic particles (10) within a plurality of vessels (1) with wash liquid (2), each of the vessels (1) having a bottom (4) and sidewalls (3) and containing a pre-wash liquid, the apparatus compris__₆. a liquid source for supplying wash liquid (2), a vacuum source for supplying a vacuum, a dispensing manifold connected to said liquid source , an aspirating manifold connected to said vacuum source, a plurality of said liquid channels (8), each of said liquid channels (8) connected to said liquid manifold, and a plurality of said vacuum channels (9), each of said vacuum channels (9) connected to said aspirating ^" manifold, each of said liquid channels (8) terminating with two or more outlets (7) for expressing wash liquid (2) into the coated vessels (1), and each of said vacuum channels (9) terminating with an inlet (6) for aspirating liquids from the vessel (1), each of said liquid channels (8) corresponding to one of said vacuum channels (9), said corresponding liquid channels (8) and vacuum channels (9) being adjacent to and coupled to one another, each of said inlets (6) being positionable adjacent to the bottom (4) of one of the plurality of vessels (1) for aspirating liquids therefrom, each of said outlets (7) being bent with respect to said inlets (6) for directing the expression of wash liquid (2) onto magnetic particles (10) attached to the sidewall (3) of one of the vessels (1) so as to dislodge the magnetic particles (10) from the sidewall (3) and wash the magnetic particles (10) by means of the λvash

14. A method for washing magnetic particles (10) within a vessel (1) containing pre-wash liquid, the method comprising the following steps:

Step A: translating a probe (5) vertically downward into the vessel (1) until the inlet (6) of the probe (5) is adjacent to the bottom (4) of the vessel (1); while simultaneous-.,

Step B: aspirating the pre-wash liquid from the vessel (1) through an inlet (6) within the probe (5); then

Step C: expressing wash liquid (2) onto the magnetic particles (lu) attached to the sidewall (3) of the vessel (1) by . an? of bent outlets (7) extending from the probe (5) with force so as to dislodge the magnetic particles (10) and wash the magnetic particles (10) with the wash liquid (2).

15. A method for washing a vessel (1) as described in claim 14 comprising the following additional steps: Step D: repeating said Steps A-C as desired for achieving multiple wash cycles.

16. A method for washing a plurality of vessels (1), each vessel (1) containing pre-wash liquid, the method comprising the following steps:

Step A: translating a plurality of probes (5) vertically downward with each probe (5) corresponding to and descending into one of the plurality of vessels (1) until the inlet (6) of each probe (5) is adjacent to the bottom (4) of its corresponding vessel (1); while simultaneously Step B: aspirating the pre-wash liquid from each of the vessels (1) through inlets (6) within each of the probes (5) ; then

Step C: expressing wash liquid (2) onto the sidewalls (3) of each of the vessels (1) by means of bent outlets (7) extending from each of the probes (5) and imparting a swirling motion to the wash liquid (2) upon the sidewalls (3) and bottom (4) of each of the vessels (1); while simultaneously

Step E: translating the plurality of probes (5) vertically upward for expressing wash liquid (2) onto the sidewalls (3) of each of the vessels (1) progressively more distal from the bottom (4) .