The present teachings relate to improving the flatness of microwell plates. Methods and apparatuses that improve the flatness of microwell plates are disclosed.
Microwell plates are used on spotting or filling work stations wherein the microwells receive assays, reagents and/or samples. The plates may conform to SBS/ANSI (Society for Biomolecular Screening/American National Standards Institute) standard dimensions and may be about 127 millimeters in length by about 85 millimeters in width. The plate may include a large number of wells. For example, some plates may have 6,144 wells or more. The small size and compact spacing of the wells makes the precise alignment of the wells on a spotting or filling work station difficult. While the plate is typically manufactured to precise dimensions, the level of flatness can deviate from the nominal value to an extent that can lead to dispensed assays, reagents and/or samples missing their targeted wells. Thus, it would be advantageous to improve the level of flatness of the plates.
The present teachings provide methods and apparatuses that improve the flatness of the microwell plates. In some aspects of the present teachings, a rigid chuck is used to improve the flatness of the microwell plate by applying a vacuum to the plate and pulling the plate against the rigid chuck. In other aspects according to the present teachings, a pair of opposing channels that extend along a length of a rigid member are used to retain the microwell plate on the rigid member and to impart a level of flatness of at least a predetermined value. In other aspects according to the present teachings, a plurality of rigid framing members each having a channel therein are disposed along the edges of a microwell plate and impart a level of flatness of at least a predetermined value to the plate. In other aspects according to the present teachings, a method of flattening the microwell plate comprises securing the plate to a rigid member so the plate has a flatness of at least a predetermined value and maintaining the plate secured to the rigid member during a subsequent spotting or filling operation. These and other features of the present teachings are set forth herein.
The skilled artisan will understand that the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the present teachings in any way.
The present teachings provide methods and apparatuses for improving the flatness of high density microwell plates. The following definitions and non-limiting guidelines must be considered in reviewing the description of the invention set forth herein.
The section headings used herein are used for organizational purposes only and are not to be construed as limiting the subject matter described in any way. Furthermore, while the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications and equivalents, as will be appreciated by those of skill in the art.
The description and specific examples, while indicating embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. Moreover, recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features, or other embodiments incorporating different combinations of the stated features. Specific examples are provided for illustrative purposes of how to make, use and practice the devices and methods of this invention and, unless explicitly stated otherwise, are not intended to be a representation that given embodiments of this invention have, or have not, been made or tested.
As used herein, the word “include” and its variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that may also be useful in the materials, compositions, devices and methods of this invention.
Referring to
Plates 26, for which flattening device 22 is configured to retain, have opposite first and second surfaces 28, 30 and a sidewall 32 therebetween, as can be seen in
Plate 26 can be made from a plastic such as polypropylene with graphite filler. It should be appreciated, however, that other materials such as, but not limited to, glass, silica, plastics, thermal conductive materials, and any other material useful to those skilled in the art can be used for plate 26. The small size and compact spacing of wells 34 make the precise alignment of wells 34 on a spotting or filling work station 20 difficult. In some embodiments plate 26 conforms to SBS/ANSI standard dimensions and is about 127 mm in length by about 85 mm in width. In some embodiments, plate 26 has at least 6,144 wells. While plate 26 is manufactured to precise dimensions, the level of flatness can deviate from the nominal value an extent that can lead to dispensed reagents and samples missing their targeted wells 34.
Flattening device 22 is operable to improve the flatness of plate 26 to a level that allows for precise alignment on spotting or filling work station 20 so that the reagents and samples can be accurately placed in the desired well. In the embodiments shown in
Referring now to FIGS. 2 and 3A-B, details of one embodiment of flattening device 22 are shown. Flattening device 22 uses a rigid plate or chuck 46 having opposite first and second surfaces 48, 50 and a sidewall 52 therebetween. Chuck 46 is precisely dimensioned to allow indexing off a portion of sidewall 52 to align on an instrument deck 24 of a work station 20. If desired, chuck 46 may include alignment features that correspond with complementary alignment features on instrument deck 24 to align chuck 46 on instrument deck 24. In some embodiments, chuck 46 has a footprint about the size of a microtiter or microwell plate conforming to SBS/ANSI dimensional standards. In other embodiments, chuck 46 may have a footprint of a differing size. Chuck 46 is more rigid than plate 26 to allow chuck 46 to improve the flatness of plate 26. Chuck 46 can be made from a variety of materials. For example, chuck 46 can be made from steel, aluminum or other metals or materials, such as a polymer, as long as the rigidity of chuck 46 is greater than that of plate 26. For example, the beveled corner 39 on plate 26 may also be used as an alignment feature.
Chuck 46 includes a central aperture 54 which extends between first and second surfaces 48, 50. A vacuum fitting 56 can be attached to chuck 46 and extends from second surface 50. Fitting 56 communicates with aperture 54 to allow a vacuum source to be connected to chuck 46, as described below.
Two recessed fluid channels 58, 60 extend longitudinally along first surface 48 of chuck 46. Two other recessed channels 62, 64 extend laterally along first surface 48 of chuck 46. Fluid channels 58, 60, 62, 64 all communicate with aperture 54 to allow a vacuum to be pulled between plate 26 and first surface 48 of chuck 46 to retain plate 26 in place and improve the flatness, as described below.
As best seen in
As best seen in
Support member 74 provides a support surface for the bottom or second surface 30 of plate 26. Support member 74 limits deformation of plate 26 due to the force of the vacuum between chuck 46 and plate 26. Support member 74 can be a stiff or rigid support or a resilient support that undergoes some deformation due to the force of the vacuum between plate 26 and chuck 46. As such, support member 74 can be a non-deformable gasket, O-ring or the like, or also function as a sealing member providing a fluid-tight seal between plate 26 and chuck 46 and made from an elastomer or other resilient material.
Fluid channels 58, 60, 62, 64 extend beneath support member 74 and allow a vacuum to be imparted to region 68 of chuck 46 both inside and outside of support member 74. Sealing member 72, support member 74 and first surface 48 of chuck 46 are dimensioned to provide a planar surface having a flatness equal to or better than a predetermined value when plate 26 is being held thereon by a vacuum. The vacuum may cause plate 26 to deform from its nominal shape and results in the predetermined level of flatness, or better, to be imparted to plate 26. The number of support members 74 and/or sealing members 72 can be increased or decreased to provide a required level of support to the bottom or second surface 30 of plate 26 to impart a desired level of flatness to plate 26. Furthermore, the width of sealing member 72 and/or support member 74 can be changed to provide a desired level of support to bottom surface 30 of plate 26. The predetermined level of flatness is chosen to allow precise positioning of plate 26 on chuck 46 and subsequently on instrument deck 24 to allow for accurate spotting and/or filling operations by work station 20. For example, a total flatness of equal to or better than 500 microns or a nominal value±250 microns or less can be the predetermined flatness level and imparted by chuck 46 to plate 26.
Chuck 46 may include alignment features to facilitate the alignment of plate 26 on chuck 46. In the embodiment shown in
Instrument deck 24, as shown in
On instrument decks 24 without opening 82 therein the chuck will have a different arrangement to account for the lack of the opening in the instrument deck. Specifically, as shown in
Referring now to
As shown in
Integrated chuck/deck 192 can use the same alignment features discussed above with reference to FIGS. 2 and 3A-B or, as shown, can use a plurality of walls or projections 194 that extend outwardly from first surface 148 of integrated chuck/deck 192. As best seen in
In some embodiments according to the present teachings, flattening device 222 comprises a flattening block 202, as shown in
Opposing side extensions 206a, 208a of opposing sidewalls 206, 208 of flattening block 202 extend above top surface 204. Extensions 206a, 208a in conjunction with top surface 204 form opposing U-shaped channels 210, 212 that face one another. Channels 210, 212 are configured to receive sidewalls 232 of plate 226 therein. Specifically, channels 210, 212 have an internal vertical height that is dimensioned to be slightly larger than the nominal thickness of sidewalls 232 of plate 226. To attach plate 226 to flattening block 202, plate 226 is slid along top surface 204 with opposing sidewalls 232 disposed in channels 210, 212. The dimensions of channels 210, 212 cause plate 226 to have a level of flatness, at least in the direction parallel to the channels, to be equal to or better than the predetermined level of flatness.
Flattening block 202 can include alignment features to facilitate the alignment of plate 226 thereon. The alignment features can include channels 210, 212, an alignment pin 214 and a plunger mechanism 216. Channels 210, 212 guide plate 226 as it is slid along top surface 204 of flattening block 202. Pin 214 engages with slot 236 of plate 226 to limit the distance along top surface 204 that plate 226 can be slid. Plunger mechanism 216 comprises a ball 218 that nominally extends slightly above top surface 204 under the bias of a spring 219. Spring 219 allows ball 218 to be plunged into and retracted below top surface 204 when subjected to a force of an appropriate magnitude. When plate 226 is slid along top surface 204, bottom surface 230 of plate 226 pushes ball 218 below top surface 204. As slot 236 in plate 226 comes into full engagement with pin 214, ball 218 is aligned with aperture 238 in plate 226. Spring 219 causes ball 218 to extend upwardly and into engagement with aperture 238. Plunger mechanism 216 retains plate 226 in this orientation on top surface 204 of flattening block 202. To remove plate 226 from flattening block 202, a sliding force of a sufficient magnitude is imparted upon plate 226 to overcome the biasing of ball 218 by spring 219. Flattening block 202 thereby retains plate 226 thereon and imparts a level of flatness to plate 226 equal to or better than the predetermined level of flatness via the interaction with channels 210, 212 and top surface 204.
Other embodiments of flattening device 322, as shown in
The framing members 321, 323 can be made from a variety of materials providing the framing members are more rigid than plate 326. For example, framing members 321, 323 can be made from steel, aluminum or other metals or from a polymer provided the rigidity is greater than that of plate 326. Framing members 321, 323 are made to precise dimensions and allow for indexing off an outer surface of one or more framing members 321, 323 to precisely position on an instrument deck. If desired, alignment features, such as pins and apertures or slots, can be employed on framing members 321, 323 and on the instrument deck to facilitate the aligning of plate 326 retained within framing members 321, 323 on an instrument deck within a work station.
Flattening device 322 can be used with less than two longitudinal framing members 321 and/or two lateral framing members 323. Specifically, any two framing members 321, 323 can be used in conjunction with one another to impart a level of flatness to plate 326 equal to or better than the predetermined value. For example, one longitudinal framing member 321 and one lateral framing member 323 can be used in conjunction with one another to form a generally “L-shaped” brace within which plate 326 is disposed.
While the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art. For example, the various features and components of the flattening devices disclosed herein can be mixed or interchanged with one another, as desired, to provide the associated benefits and/or advantages of using such features or components. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
This application is a continuation of U.S. patent application Ser. No. 11/769,784 filed Jun. 28, 2007, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 11769784 | Jun 2007 | US |
Child | 13092781 | US |