Abstract:
A cell suspension that contains a cell group from which unwanted components have been removed by efficiently washing the cell group is recovered. A centrifuge container ( 1 ) includes a cylindrical container main body ( 2 ) that accommodates a cell suspension and is rotated with a bottom portion ( 2   a ) being directed radially outward; a supernatant suction tube ( 4 ) that has a first opening ( 4   a ) at a position in the depth direction of the container main body ( 2 ) and that suctions a supernatant obtained by centrifuging the cell suspension, in the radial direction of the container main body ( 2 ); and a washing-fluid discharge tube ( 3 ) that have a second opening ( 3   a ) at a position in the depth direction of the container main body ( 2 ) and that discharge a washing fluid in the axial direction toward the bottom portion ( 2   a ) of the container main body ( 2 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a centrifuge container. 
       BACKGROUND ART 
       [0002]    There is a conventionally known centrifuge separator in which a centrifuge container accommodating a cell suspension in which fat-derived cells are isolated by breaking down fat tissues is rotated around an axis located away from the centrifuge container, thereby separating components contained in the cell suspension according to their specific gravities (see PTL 1). 
         [0003]    The centrifuge container is formed into a substantially cylindrical shape one end of which is closed. When the centrifuge container is rotated with the closed end being directed radially outward, components with higher specific gravities are moved to the closed end and are separated in descending order of specific gravity from the closed end. 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         {PTL 1} PCT International Publication No. WO 05/012480 Pamphlet 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    One problem, however, is that a cell group separated in a bottom portion of the centrifuge container when the cell suspension is centrifuged is formed into a centrifugally solidified pellet. Specifically, if the cell group is formed into a pellet, it is difficult to remove the centrifuged cell group from the centrifuge container by suction. Furthermore, there is a case where the cell group is formed into a pellet while unwanted components, such as proteolytic enzyme and fat, are incorporated in the cell group during the centrifugation, and, in that case, it is difficult to remove the unwanted components. 
         [0006]    The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a centrifuge container capable of recovering a cell suspension that contains a cell group from which unwanted components have been removed by efficiently washing the cell group. 
       Solution to Problem 
       [0007]    In order to achieve the above-described object, the present invention provides the following solutions. 
         [0008]    According to one aspect, the present invention provides a centrifuge container including: a cylindrical container main body that accommodates a cell suspension and is rotated with a bottom portion being directed radially outward; a supernatant suction tube that has a first opening at a position in the depth direction of the container main body and that suctions a supernatant obtained by centrifuging the cell suspension, from the first opening, in the radial direction of the container main body; and a washing-fluid discharge tube that has a second opening at a position in the depth direction of the container main body and that discharges a washing fluid from the second opening, in the axial direction toward the bottom portion of the container main body. 
       Advantageous Effects of Invention 
       [0009]    According to the present invention, an advantage is afforded that it is possible to recover a cell suspension containing a cell group from which unwanted components have been removed by efficiently washing the cell group. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is a longitudinal sectional view showing a centrifuge container according to an embodiment of the present invention. 
           [0011]      FIG. 2  is a longitudinal sectional view showing a state where a cell suspension is accommodated in the centrifuge container shown in  FIG. 1 . 
           [0012]      FIG. 3  is a longitudinal sectional view showing a state where the cell suspension accommodated in the centrifuge container shown in  FIG. 1  is centrifuged. 
           [0013]      FIG. 4  is a longitudinal sectional view for explaining a step of suctioning a supernatant from the cell suspension centrifuged in  FIG. 3 . 
           [0014]      FIG. 5  is a longitudinal sectional view showing a step of supplying a washing fluid in the state shown in  FIG. 4 . 
           [0015]      FIG. 6  is a longitudinal sectional view showing a step of suctioning and recovering the cell suspension resuspended in the centrifuge container shown in  FIG. 1 . 
           [0016]      FIG. 7  is a longitudinal sectional view showing a first modification of the centrifuge container shown in  FIG. 1 . 
           [0017]      FIG. 8A  is a partially-enlarged longitudinal sectional view showing a step of supplying a cell suspension, using the centrifuge container shown in  FIG. 7 . 
           [0018]      FIG. 8B  is a partially-enlarged longitudinal sectional view showing a step of suctioning a supernatant, using the centrifuge container shown in  FIG. 7 . 
           [0019]      FIG. 8C  is a partially-enlarged longitudinal sectional view showing a step of supplying a washing fluid, using the centrifuge container shown in  FIG. 7 . 
           [0020]      FIG. 8D  is a partially-enlarged longitudinal sectional view showing a step of suctioning and recovering a cell group, using the centrifuge container shown in  FIG. 7 . 
           [0021]      FIG. 9  is a longitudinal sectional view showing a second modification of the centrifuge container shown in  FIG. 1 . 
           [0022]      FIG. 10  is a longitudinal sectional view showing a third modification of the centrifuge container shown in  FIG. 1 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    A centrifuge container  1  according to an embodiment of the present invention will be described below with reference to  FIGS. 1 to 6 . 
         [0024]    As shown in  FIGS. 1 to 6 , the centrifuge container  1  according to this embodiment is provided with a cylindrical container main body  2  which is closed at one end forming a bottom portion  2   a , a fluid introduction tube (suspension supply tube, washing-fluid discharge tube)  3  that introduces a cell suspension A ( FIG. 2 ) and a washing fluid B ( FIG. 5 ) to the container main body  2 , a supernatant suction tube  4  that suctions a supernatant C ( FIG. 3 ) centrifuged in the container main body  2 , and a cell suction tube  5  that suctions a cell suspension A′ ( FIG. 6 ) that contains a cell group D ( FIG. 3 ) centrifuged in the container main body  2 . 
         [0025]    The container main body  2  is formed into a substantially cylindrical shape and has an opening  2   b  at one end and the bottom portion  2   a  at the other end, which is closed. The bottom portion  2   a  is formed into a tapered inner-surface shape, whose diameter is gradually reduced toward the tip. 
         [0026]    The container main body  2  is sealed when the opening  2   b  is closed by means of a lid member  6 . 
         [0027]    The fluid introduction tube  3 , the supernatant suction tube  4 , and the cell suction tube  5  are fixed in the lid member  6 , the tubes passing through the center thereof and the tips of the tubes being disposed in the container main body  2 . 
         [0028]    As shown in  FIG. 3 , the fluid introduction tube  3  has a tip opening  3   a  disposed at the supernatant C side with respect to an interfacial surface E between the cell group D and the supernatant C, which are centrifuged in the container main body  2 . The tip opening  3   a  opens toward the bottom portion  2   a  of the container main body  2  so as to discharge the supplied cell suspension A and washing fluid B toward the bottom portion  2   a  of the container main body  2 . 
         [0029]    The supernatant suction tube  4  has a tip opening  4   a  that opens radially outward at substantially the same position as the tip opening  3   a  of the fluid introduction tube  3 . Thus, when the supernatant C in the container main body  2  is suctioned from the tip opening  4   a , the supernatant C is radially suctioned from the tip opening  4   a , disposed at the supernatant C side with respect to the interfacial surface E between the cell group D and the supernatant C. 
         [0030]    The cell suction tube  5  has a tip opening  5   a  disposed at a position close to the bottom portion  2   a  of the container main body  2 . Thus, all the cell suspension A′ containing the cell group D, accommodated in the container main body  2 , can be suctioned to the outside of the container main body  2 . 
         [0031]    Pumps (not shown) are connected to the fluid introduction tube  3 , the supernatant suction tube  4 , and the cell suction tube  5 , which are connected to the container main body  2 , such that the fluids A, B, C, and A′ therein can be transferred. 
         [0032]    The operation of the thus-configured centrifuge container  1  according to this embodiment will be described below. 
         [0033]    In order to separately recover the desired cell group D from the cell suspension A by using the centrifuge container  1  of this embodiment, the centrifuge container  1  is set in a centrifuge separator (not shown), and, as shown in  FIG. 2 , the cell suspension A is externally supplied to the container main body  2  through the fluid introduction tube  3 . In this state, the centrifuge separator is operated to rotate the centrifuge container  1 . 
         [0034]    The centrifuge container  1  is rotated with the bottom portion  2   a  of the container main body  2  being directed radially outward, thereby centrifugalizing the cell suspension A accommodated in the container main body  2 . Thus, various components contained in the cell suspension A are centrifuged according to the differences in their specific gravities, as shown in  FIG. 3 . 
         [0035]    Specifically, since the bottom portion  2   a  of the container main body  2  is formed into the tapered inner-surface shape, the cell group D, with a higher specific gravity, contained in the cell suspension A is collected at the tip of the bottom portion  2   a  along the tapered inner surface. Thus, the cell group D sinks to the tip of the bottom portion  2   a  of the container main body  2 , thereby being separated from the rest of the supernatant C. 
         [0036]    In this state, the centrifuge separator is stopped, and the centrifuge container  1  is disposed such that the bottom portion  2   a  of the container main body  2  is directed vertically downward. Then, as shown in  FIG. 4 , the supernatant C in the container main body  2  is suctioned through the supernatant suction tube  4 . Since the tip opening  4   a  of the supernatant suction tube  4  is directed radially outward, the ambient supernatant C is suctioned radially inward. Thus, only the supernatant C can be suctioned while avoiding a disadvantage that the cell group D located in the bottom portion  2   a  of the container main body  2  is suctioned. 
         [0037]    Next, as shown in  FIG. 5 , the washing fluid B is supplied to the container main body  2  through the fluid introduction tube  3 . Since the tip opening  3   a  of the fluid introduction tube  3  is disposed at the supernatant C side with respect to the interfacial surface E between the supernatant C and the cell group D and is directed toward the bottom portion  2   a  of the container main body  2 , the supplied washing fluid B is blown out toward the cell group D located in the bottom portion  2   a  of the container main body  2 . Thus, even when the cell group D becomes solidified like a pellet, when the washing fluid B is blown out, the cell group D can be unsolidified and resuspended in the washing fluid B. 
         [0038]    Specifically, during the centrifugation, some of unwanted components, such as proteolytic enzyme and fat, are incorporated into the cell group D, which is moved to the bottom portion  2   a  side of the container main body  2  according to the specific gravity, thereby forming a pellet that is solidified together with the cell group D. However, when the washing fluid B is blown out to unsolidify the pellet-like cell group D, the incorporated unwanted components can be released. 
         [0039]    The centrifuge container  1  in which the cell suspension A resuspended in this way is accommodated is rotated again through the operation of the centrifuge separator, to execute centrifugation. Thus, the cell group D in which the fraction of unwanted components has been reduced can be separated. Then, after the supernatant C is removed with suction similarly to the above-described manner, a small amount of washing fluid B is supplied to the container main body  2  through the fluid introduction tube  3 . 
         [0040]    As a result, the washing fluid B is again blown out to the cell group D, thus forming a cell suspension A′ in which the pellet-like cell group D is unsolidified and resuspended. In this state, as shown in  FIG. 6 , the cell suspension A′ accommodated in the container main body  2  is suctioned through the cell suction tube  5 . Since the tip opening  5   a  of the cell suction tube  5  is disposed close to the bottom portion  2   a  of the container main body  2 , all of the cell suspension A′ in the container main body  2  is recovered by suction. 
         [0041]    In this way, according to the centrifuge container  1  of this embodiment, the washing fluid B can be discharged so as to be blown out to the cell group D, and, even when the cell group D separated through the centrifugation is solidified like a pellet, it is possible to unsolidify the cell group D to remove unwanted components and to easily perform suction for recovery. 
         [0042]    Note that, in this embodiment, the supernatant suction tube  4  and the fluid introduction tube  3  are formed by separate piping; however, instead of this, as shown in  FIG. 7 , they may be structured by a common path  7  in which a valve  8  is provided for switching between the suction of the supernatant C and the discharge of the fluids A and B. 
         [0043]    In the example shown in  FIG. 7 , a tip opening  7   a  of the common path  7 , which is concentrically disposed radially outward from the cell suction tube  5 , is disposed at the supernatant C side with respect to the interfacial surface E between the centrifuged supernatant C and cell group D, and the valve  8  formed of a valving element made of an elastic member is disposed on the tip opening  7   a.    
         [0044]    Tip openings  7   b  used for suctioning the supernatant C are radially formed so as to pass through the outer wall of the common path  7 . Furthermore, the tip opening  7   a , used for discharging the cell suspension A and the washing fluid B, is formed at the end of the common path  7  in the direction of the axis and is a gap between the common path  7  and the cell suction tube  5  facing in the direction toward the bottom portion  2   a  of the container main body  2 . 
         [0045]    As shown in  FIGS. 8A to 8D , the valve  8  is formed into a ring-plate shape, the outer-circumferential edge thereof is secured on the end surface of the common path  7 , and the inner-circumferential edge thereof can be displaced in the axial direction. Furthermore, a step portion  5   b  against which the inner-circumferential edge of the valve  8  butts is provided on the outer-circumferential surface of the cell suction tube  5 . 
         [0046]    With this structure, when the cell suspension A or the washing fluid B is supplied through the common path  7 , as shown in  FIGS. 8A and 8C , the inner-circumferential edge of the valve  8  is displaced toward the bottom portion  2   a  of the container main body  2  by the pressure of the supplied fluid, thus opening the valve  8  and discharging the cell suspension A or the washing fluid B toward the bottom portion  2   a  of the container main body  2 . On the other hand, when the supernatant C is suctioned, as shown in  FIG. 8B , the inner-circumferential edge of the valve  8  butts against the step portion  5   b , provided on the outer-circumferential surface of the cell suction tube  5 , thus closing the valve  8  and suctioning the supernatant C radially from the tip openings  7   b . Then, as shown in  FIG. 8D , the cell suspension A′ containing the cell group D is recovered with suction through the cell suction tube  5 , located at the center. 
         [0047]    By doing so, the structure can be simplified by sharing the path. 
         [0048]    Furthermore, as shown in  FIGS. 9 and 10 , the fluid introduction tube  3  and the cell suction tube  5  may be integrally formed.  FIG. 9  illustrates a case where a common path representing a combination of the fluid introduction tube  3  with the cell suction tube  5  and the supernatant suction tube  4  are arranged in parallel.  FIG. 10  illustrates a case where a common path representing a combination of the fluid introduction tube  3  with the cell suction tube  5  and the common path  7  (the supernatant suction tube  4 ) are concentrically arranged. The common path representing the fluid introduction tube  3  and the cell suction tube  5  can be selectively switched by a three-way valve or check valve (not shown) between the supply of the cell suspensions A and A′ and the washing fluid B, and recovery of the cell suspension A′ containing the cell group D by suction. 
         [0049]    Since the cell suction tube  5  needs to recover almost all the cell suspension A′ existing in the container main body  2  by suction, the tip opening  5   a  thereof needs to be disposed at a position close to the bottom portion  2   a . When the washing fluid B is supplied through the common path  7 , which is integrally formed with the cell suction tube  5 , it is possible to discharge the washing fluid directly to the pellet-like cell group D, formed through centrifugation, thus unsolidifying the cell group D more effectively. 
       REFERENCE SIGNS LIST 
       [0000]    
       
         A, A′ cell suspension 
         B washing fluid 
         C supernatant 
         D cell group 
           1  centrifuge container 
           2  container main body 
           2   a  bottom portion 
           3  fluid introduction tube (washing-fluid discharge tube, suspension supply tube) 
           3   a ,  7   a  tip opening (second opening) 
           4  supernatant suction tube 
           4   a ,  7   b  tip opening (first opening) 
           5  cell suction tube 
           5   a  tip opening 
           5   b  step portion 
           6  lid member 
           7  common path 
           8  valve