Abstract:
A machine which has a platform for a specimen container and is constructed to spin the platform to produce centrifugation of the specimen is provided with a linkage that can selectively convert the spinning to a more complex form of motion effective to produce disruption of the specimen on the platform. Preferably, the linkage causes tilting of the platform about the axis of spinning, thereby providing a conical form of motion. In a preferred embodiment, the linkage is constructed to provide the complex motion when the platform is rotated in one direction and to provide spinning when the platform is rotated in the opposite direction.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to an apparatus for processing samples, such as chemical and biological samples, and, more particularly, concerns such an apparatus which can perform disruption as well as centrifugation. 
         [0002]    Today, chemical and biological samples are typically prepared in titer plates or individual vials. An extracting solvent or buffer may be added, if needed, and the samples are then shaken, either manually or by means of a mechanical disrupter, homogenizer, shaker, agitator, or vortexer (hereafter referred to generically as a “disrupter”). Thereafter, the samples are removed from the mechanical device and transferred to a centrifuge, where they are spun high speed to effect separation. This includes, but is not limited to separation of solids from liquids, separation of liquids of different density, and collection of DNA or RNA. 
         [0003]    Since disruption and centrifugation involve two different pieces of equipment, the operator must manually transfer the sample containers from one piece of equipment to the other. This requires him to be present for both steps and requires time and effort to transfer samples and start the operation of the second piece of equipment. The skill and time of the operator could be utilized in much more meaningful and profitable ways. 
         [0004]    It is therefore an object of the present invention to provide a sample processing apparatus which can perform both disruption and centrifugation of samples. It is specifically an object of the invention that the apparatus be capable of transitioning between disruption and centrifugation modes of operation automatically and with minimal operator intervention, other than to select the mode of operation, and without the operator handling samples, other than to insert or remove them from the apparatus. It is specifically contemplated that the operator should not be required to achieve a change in the mode of operation of the apparatus. 
         [0005]    It is yet another object of the invention to provide a sample processing apparatus which is reliable in construction, yet relatively easy and convenient to use. 
         [0006]    In accordance with one aspect of the present invention, a machine which has a platform for specimen container and which is constructed to spin the platform to produce centrifugation of the specimen is provided with a linkage that can selectively convert the spinning to a more complex form of motion effective to produce disruption of the specimen on the platform. Preferably, the linkage causes tilting of the platform relative to the axis of spinning, thereby providing a conical motion of the platform central axis and a complex, oscillatory motion of the samples. In a preferred embodiment, the linkage is constructed to provide the complex motion when the drive mechanism is rotated in one direction and to provide spinning of the platform when the drive mechanism is later rotated in the opposite direction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The foregoing brief description and further objects, features and advantages of the present invention will be understood more completely from the following detailed description of the presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, with reference being had to the accompanying drawings in which: 
           [0008]      FIGS. 1-5  are simplified perspective views illustrating the operation of a processing apparatus  10  embodying the present invention; 
           [0009]      FIG. 6  is a simplified perspective view of apparatus  10 , with the two offsets  16  and  18  cut away to show interior details; and 
           [0010]      FIG. 7  is a simplified perspective view, similar to  FIG. 6 , with offset  16  removed. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIGS. 1-5  are perspective views illustrating the operation of a processing apparatus  10  embodying the present invention. Apparatus  10  has two modes of operation, being capable of performing as both a disrupter ( FIG. 1 ) and a centrifuge ( FIG. 5 ). A container containing the sample (not shown) is mounted on a sample plate  14 , which is mounted on a top offset  16 , which is, in turn, mounted on a bottom offset  18 . Sample plate  14 , top offset  16 , and bottom offset  18  are all mounted for rotation about a shaft  12 . 
         [0012]    The mode of operation will depend upon the direction of movement of sample plate  14 . A motor drive, for example via a pulley (not shown), is applied to bottom offset  18 . In order to enter the disrupter mode, bottom offset  18  is rotated counterclockwise. As will be explained in more detail below, counterclockwise movement of bottom offset  18  relative to top offset  16  produces an interaction between the two offsets which causes the offset  16 , sample plate  14  a sprag clutch  22  (discussed further below), and an upper portion of shaft  12  to tilt, as a unit, relative to offset  18  and a lower portion of shaft  12  (compare  FIGS. 1 and 5 ). Sample plate  14  and offsets  16  and  18  then rotate counterclockwise, as a unit, about shaft  12 . This tilted rotation of sample plate  14 , which has an oscillatory component to it as well, produces complex, oscillatory movement and disruption of the sample. 
         [0013]    When disruption is complete, the motor drive of bottom offset  18  is slowed and then reversed, so that it rotates clockwise. Clockwise rotation of offset  18  relative to offset  16 , through their interaction, then brings the two offsets and sample plate  14  into axial alignment with shaft  12  (see  FIG. 5 ). Rotation of bottom offset  18  about shaft  12  can then be accelerated, bringing sample plate  14  up to a rotational speed at which apparatus  10  will function as a centrifuge. 
         [0014]    Those skilled in the art will appreciate that the transition between disrupter and centrifuge modes of operation could simply be accomplished through operator manipulation of controls. However, it is well within the skill of the art to incorporate automatic control, including timers, which can be preset to desired durations for disruption and centrifugation. Of course, automatic control also allows presetting of operating speeds, acceleration, and other operating parameters. 
         [0015]      FIG. 6  is a perspective view of apparatus  10 , with the two offsets  16  and  18  cut away to show interior details, and  FIG. 7  is a perspective view, similar to  FIG. 6 , with offset  16  removed. As may be seen, shaft  12  is made up of a lower shaft L and a top shaft T, which are joined by a universal joint U. Bearings  20  are provided to permit free rotation of sample plate  14  and offsets  16  and  18  relative to shaft  12 . 
         [0016]    A sprag clutch  22  is provided between sample plate  14  and top offset  16 , which holds sample plate  14  to shaft  12 , while permitting free rotation about top offset  16 , during disruption (counterclockwise rotation of offset  18 ). At the same time, a sprag cover  23  mounted on shaft  12  above platform  14  holds the platform to sprag clutch  22 . This results in transfer of the complex motion to sample plate  14  with it not rotating about shaft  12 . When apparatus  10  switches modes (clockwise rotation of offset  18  transferred to offset  16 ) clutch  22  permits free clockwise rotation of top offset  16  and holds it to sample plate  14 , transferring rotational motion to sample plate  14 . 
         [0017]    Top offset  16  and bottom offset  18  have opposed surfaces  24 ,  26 , which are formed at an acute angle to the axis of shaft  12 . That is, they are not in a plane perpendicular to the axis of shaft  12 . A bearing  28  permits relative rotation of offsets  16 ,  18  about an axis perpendicular to surfaces  24 ,  26 . 
         [0018]    In operation, when bottom offset  18  is driven counterclockwise, it will rotate relative to top offset  16  about the shaft  12  until its most counterclockwise edge  30  comes into contact with the most clockwise edge  32  of top offset  16 . As bottom offset  18  rotates counterclockwise relative to top offset  16 , top offset  16  also rotates about bearing  28  and begins to tilt, carrying sample plate  14  with it. When edges  30  and  32 , come into contact, bottom offset  18  pushes tilted top offset  16 , driving sample plate  14  in a conical pattern. As can be seen in  FIG. 2  (showing the opposite side of apparatus  10 ), at this time, the most clockwise edge  34  of bottom offset  18  and most counterclockwise edge  36  of the top offset  16  are far apart. 
         [0019]    Later, when bottom of offset  18  is driven clockwise, edge  34  moves towards edge  36  (see  FIG. 4 ), and the movement causes top offset  16  to rotate about bearing  28  towards an upright position, causing the axis of sample plate  14  to shift towards alignment with the axis of shaft  12 . When edges  34  and  36  come into contact (see  FIG. 5 ), the axes of sample plate  14  and shaft  12  are in alignment, and bottom offset  18  pushes top offset  16  into clockwise rotation. Through the action of sprag clutch  22 , sample plate  14  is also brought into clockwise rotation, enabling centrifuge operation. 
         [0020]    When centrifugation is complete, the sample can be removed by the operator and replaced with a new sample, which can be subjected to both disruption and centrifugation. 
         [0021]    While the example shown herein uses a linkage to impart a first type of motion in one direction and a second type of motion in the other direction, the direction of rotation need not change. Instead, the change in type of motion can occur even if rotation is in the same direction for both types of motion. In this case, the additional linkage causing the more complex type of motion might take a different form or be eliminated. 
         [0022]    Generally, the disruption motion desired in the preferred embodiment is an oscillatory tilting of the axis of rotation of the sample plate, coupled with rotation of the tilted axis. In the centrifuge mode, the sample plate is to be rotated about the axis of rotation. By switching between these modes after a predetermined time, or after a parameter indicative of sample disruption has occurred, both required processes can be performed in the same apparatus without having to change samples and/or vessels. 
         [0023]    Rather than switch the type of motion after a predetermined time, other parameters indicative of the completion of the disruption or other first mode of motion can be used. For example, the system could measure the number of cycles of motion executed during the first mode, or could include a detector to determine when the proper amount of separation or disruption has been achieved. Any parameter sufficient to indicate when the first mode is complete may be used instead of a timer. Moreover, the switch between the two types of motion could be manual, as an operator may wish to activate such switch based upon a visual inspection of the sample as it undergoes the processing via the first type of motion. 
         [0024]    Although a preferred embodiment of the invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that many additions, modifications, and substitutions are possible without departing from the scope and spirit of the invention as defined by the accompanying claims. For example, a variety of gearing and bearing arrangement may be used to alter the type of motion imparted on the sample.