Abstract:
A Microtiter plate centrifuge is disclosed. The centrifuge includes a motor assembly a shaft, extending vertically from the motor assembly, a rotor assembly, attached to the shaft, the rotor assembly including at least two slots, symmetrically positioned, with respect to the shaft and a channel corresponding to each of said slots. The channels extending from the rotor assembly are suitable for holding Microtiter plates in a vertical position. Also included is a bottom plate engaging a brake pad, which when engaged creates sufficient friction to halt rotation of the rotor assembly.

Description:
FIELD OF THE INVENTION  
       [0001]    This invention relates to the field of centrifuge medical devices and, more particularly, to microtiter plate centrifuges. 
       BACKGROUND OF THE INVENTION  
       [0002]    Methods for separating solid component from fluid are well-known in the medical arts, for example. In application, vials are placed in tube sleeves of a centrifuge and are then spun at various speeds. The centrifugal force generated by the spinning vials causes the heavier particles within the vial to be forced to the outer edge or lower part of the vial. 
         [0003]    In another type of centrifuge, for spinning Microtiter and/or PCR plates, the Microtiter and/or PCR plates are placed horizontally in swinging trays and are then spun up to a substantially vertical position. PCR plates represent a specific type of Microtiter plate that is made of thin plastic that allows fast transfer of heat to samples and, thus, they work well for Thermal Cycling applications. 
         [0004]    The swing out trays are typically sized to fit common sample plates, whether Microtiter or PCR However, such Microtiter and/or PCR plate centrifuges are relatively large and heavy, e.g., having an approximate 14 inch×14 inc footprint or larger; are expensive; are complicated to operate as speed and run time must be programmed; have a relatively long processing time as the large swing out rotor requires 20 to 40 seconds to reach speed and an equal amount of time to decelerate to a stop and require substantial safety features, such as a lid latching system. 
         [0005]    Hence, There is a currently a need for a lightweight and simple to operate Microtiter plate centrifuge. 
       SUMMARY OF THE INVENTION  
       [0006]    A Microtiter plate centrifuge is disclosed. The centrifuge includes a motor assembly with a shaft, extending vertically from the motor assembly, a rotor assembly, attached to the shaft, the rotor assembly including at least two slots, symmetrically positioned, with respect to the shaft and a channel corresponding to each of said slots. The channels extending from the rotor assembly are suitable for holding Microtiter plates in a vertical position. Also included is a bottom plate engaging a brake pad, which when engaged creates sufficient friction to halt rotation of the rotor assembly. 
         [0007]    These and other aspects and advantages of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. Moreover, the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES  
         [0008]    In the Drawing 
           [0009]      FIG. 1  illustrates a conventional Microtiter plate/PCR plate centrifuge; 
           [0010]      FIG. 2  illustrates a prospective view of an exemplary embodiment of a PCR plate centrifuge in accordance with the principles of the invention; 
           [0011]      FIG. 3  illustrates a top view of a plate holding rotor of the exemplary PCR plate centrifuge shown in  FIG. 2 ; 
           [0012]      FIG. 4  illustrates a cross-sectional view of the exemplary PCR plate centrifuge shown in  FIG. 2 ; and 
           [0013]      FIG. 5  illustrates a second cross-sectional view of the exemplary embodiment of the invention shown in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]      FIG. 1  illustrates a cross-section view of a conventional Microtiter/PCR plate centrifuge  100 , wherein generally oppositely positioned horizontal trays  110  (position A) are attached via a gimbaled or hinged connection  120  to a rotatable arm  125 . As the rotatable arm  125  is spun up to a desired speed, by an application of an input voltage (not shown) to a motor unit  130 , the horizontal trays  110  are swung out to a substantially vertical position (position B). While in this vertical position, any PCR plate (not shown) positioned within trays  110  are also vertically positioned and centrifugal force forces solid materials within the PCR plates to be forced to the bottom of the vials within the PCR plates. 
         [0015]      FIG. 2  illustrates a prospective view of an exemplary embodiment of a Microtiter/PCR plate centrifuge  200  in accordance with the principles of the invention. In this exemplary embodiment, a top, rotatable, plate  210  (i.e., a rotor) includes at least one set of substantially oppositely positioned slots  220 . Slots  220  represent openings to vertically positioned chambers  230 . Plate  210  is further connected to a shaft  240  which is attached to motor assembly  250 . Also shown are PCR plate  260  vertically inserted into chambers  230  through openings (slots)  220 . In one aspect of the invention, the set of slots  220  is symmetrically positioned with respect to the shaft connection to plate  210   
         [0016]      FIG. 3  illustrates a top view of the rotatable plate  210  showing the one set of oppositely positioned slots  220  leading to corresponding chambers, with plates  260  positioned in chambers  230 . The use of oppositely positioned chambers provides for balancing of the spinning rotatable plate  210  to avoid vibrations. In addition, one skilled in the art would recognize that more than one set of oppositely positioned slots  220  may be incorporated into plate  210 . The number of sets may depend on the size of plate  210 , the size of slot  210  and the orientation of adjacent slots. 
         [0017]      FIG. 4  illustrates a cross-sectional view of the exemplary Microtiter plate centrifuge shown in  FIG. 2 . As illustrated, extending substantially perpendicular from top rotatable plate (rotor)  210  are chambers (channels)  230 . Plate  210  is held in position on shaft  240  by containment devices  420 . Shaft  240  is attached to motor assembly  250 . Although channels  230  as shown as having solid walls, it would be recognized that channels  230  may also be composed of a flexible material, e.g., mesh, cloth, etc. 
         [0018]    Also shown is bottom plate  410 , which provides support for motor assembly  250 . Bottom plate  410  may further be attached to a lower end of channels (chambers)  230  to retain channels  230  in a rigid configuration. In this case, the assembly of top plate  210 , channels  230  and bottom plate  410  responds as a single unit as the motor assembly  250  causes the rotation of top plate  210 . In another aspect of the invention, the chambers may be suspended from the top plate  210  without fixed attachment to the bottom plate  410 . In this case, the bottom plate  410  may be attached to shaft  240 . Thus, as the top plate  210  and channels  230  are rotated, bottom pate  410  also rotates. 
         [0019]      FIG. 5  illustrates a second cross-sectional view of device  500  incorporating the vertical plate centrifuge  200  shown in  FIG. 2 . Device  500  includes a housing  510  attached to a base plate  580 . A lid  520 , having a hinged attachment to body (housing)  510  allows access to slot  220  in assembly  200  through an opening in housing  510 . In one aspect, lid  520 , when open, allows access to at least one slot  220  in top plate  210 . The top plate  210  may be manually rotated to allow access to another one of the slots in top plate  210 . 
         [0020]    Also shown are lid open button  530 , which is used to open lid  520 . Lid  520  may be spring loaded and when the lid open button  530  is depressed, lid  520  springs open. In addition, when lid  520  is closed, sliding switch  540  is engaged. Sliding switch  540  acts as a safety switch to prevent activation of the motor assembly  250  unless the lid is in a closed position. That is sliding switch  540  prevents/allows a voltage to be applied to run switch  550 . Thus, run switch  550  operates in conjunction with slide switch  540  to apply a voltage to motor assembly  250 . In addition, when run switch  550  is depressed and held, a brake pad  570 , which normally engages bottom plate  410 , is moved away from bottom plate  410  to allow bottom plate  410  to rotate as motor assembly  250  causes top plate  210  to rotate. When pressure is removed from run switch  550 , brake pad  570  returns to its original position against bottom plate  410 . Brake pad  570  creates friction that acts to slow down and stop the rotation of bottom plate  410 . As would be recognized, brake pad may be held in a normally engaging position by a spring mechanism (not shown). 
         [0021]    Although switch  550  is described as a momentary switch, it would be recognized that switch  550  may be a toggle switch, wherein one depression acts to activate the motor assembly  250  and position brake pad  570  away from the bottom plate  410  and a second depression causes deactivation of the motor assembly  250  and brake pad  570  is positioned against bottom plate  410 . In aspect the switch  550  may be a single-pole switch that allows voltage to be applied to motor assembly  250  when in a closed position (for a normally open switch) and in an open position (for a normally closed switch). 
         [0022]    While there has been shown, described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.