Abstract:
The problem of a specimen being vibrated during supply or drainage of a liquid such as a culture solution can be avoided, thus allowing acquisition of a stable image. The invention provides a culturing system including a main container having an opening facing upward, accommodating a culture vessel containing a biological specimen, and having an inner space maintained at a predetermined incubation environment; and a nozzle fixed to the main container and inserted into the culture vessel through the opening of the culture vessel to supply or drain a liquid into or from the culture vessel. The main container includes a transparent portion through which the biological specimen in the main container can be externally observed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to culturing systems. 
         [0003]    This application is based on Japanese Patent Application No. 2008-178038, the content of which is incorporated herein by reference. 
         [0004]    2. Description of Related Art 
         [0005]    In a known simplified CO 2  incubator in the related art, a biological specimen is contained together with a culture solution to examine the specimen while maintaining the activity thereof over a long period of time (see, for example, Japanese Unexamined Patent Application, Publication No. 2004-141143). 
         [0006]    This CO 2  incubator has tubes provided so as to extend through a lid member to, for example, circulate the culture solution inside. 
         [0007]    In the CO 2  incubator disclosed in the above publication, however, because the tubes are directly connected to, for example, circulate the culture solution, pulsations for circulating the culture solution are transmitted to the CO 2  incubator via the tubes. This causes a problem in that the specimen contained in the CO 2  incubator is vibrated, and accordingly, an observation image is vibrated. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    An object of the present invention, which has been made in light of the above circumstances, is to provide a culturing system that can avoid the problem of a specimen being vibrated during supply or drainage of a liquid such as a culture solution, thus allowing acquisition of a stable image. 
         [0009]    To achieve the above object, the present invention provides the following solutions. 
         [0010]    An aspect of the present invention is a culturing system that includes a main container having an opening facing upward, accommodating a culture vessel containing a biological specimen, and having an inner space maintained at a predetermined incubation environment; and a nozzle fixed to the main container and inserted into the culture vessel through the opening of the culture vessel to supply or drain a liquid into or from the culture vessel. The main container includes a transparent portion through which the biological specimen in the main container can be externally observed. 
         [0011]    According to the above aspect, it is possible to accommodate the culture vessel in the main container, to maintain the inner space of the main container at the predetermined incubation environment, and to observe changes over time in the biological specimen in the main container through the transparent portion while supplying or draining the liquid into or from the culture vessel through the nozzle. In this case, the nozzle is not in direct contact with the culture vessel because the nozzle is fixed to the main container with the end thereof inserted into the culture vessel. This inhibits transmission of, for example, pulsations of a pump occurring in the nozzle during the supply or drainage of the liquid through the nozzle to the culture vessel, thus preventing vibration of the biological specimen in an observation image. 
         [0012]    In the above aspect, the main container may include a base member having an opening facing upward and a lid member sealing off the opening of the base member, the base member may include a bottom portion on which the culture vessel is mounted and a peripheral wall extending upward from the bottom portion, and the nozzle may be fixed to the lid member. 
         [0013]    In this case, because the nozzle is fixed to the lid member, which is separated from the base member with the culture vessel mounted on the bottom portion thereof, the transmission of vibrations of the nozzle to the culture vessel can be further inhibited, thus allowing more stable examination. 
         [0014]    In the above configuration, a damper may be disposed between the base member and the lid member to inhibit transmission of vibrations therebetween. 
         [0015]    In this case, the damper inhibits the transmission of vibrations between the base member and the lid member. Even if the lid member is vibrated by pulsations of the nozzle during the supply or drainage of the liquid, the damper can inhibit transmission of the vibrations to the base member and the culture vessel, thus allowing stable examination as a result of alleviated vibration of the biological specimen. 
         [0016]    In the above aspect, a damper may be disposed between the main container and the nozzle to inhibit transmission of vibrations therebetween. 
         [0017]    In this case, the damper inhibits the transmission of vibrations between the main container and the nozzle. Even if the nozzle experiences pulsations during the supply or drainage of the liquid, the damper can inhibit transmission of the vibrations to the main container, thus allowing stable examination as a result of alleviated vibration of the biological specimen. 
         [0018]    In the above configuration, a support may be provided on the bottom portion of the base member so as to support the culture vessel, and a damper may be disposed between the support and the culture vessel to inhibit transmission of vibrations therebetween. 
         [0019]    In this case, the damper inhibits the transmission of vibrations between the support and the culture vessel. Even if the support is vibrated during the supply or drainage of the liquid, the damper can inhibit transmission of the vibrations to the culture vessel, thus allowing stable examination as a result of alleviated vibration of the biological specimen. 
         [0020]    In the above configuration, a support may be provided on the bottom portion of the base member so as to support the culture vessel in contact with the underside of the culture vessel. 
         [0021]    Some types of culture vessels have a leg portion for raising the bottom portion on the periphery of the bottom portion. If the height of the leg portion varies depending on the type of culture vessel, the level of the biological specimen varies accordingly. 
         [0022]    The above configuration, in which the support is disposed so as to support the culture vessel in contact with the underside thereof, prevents variations in the level of the biological specimen under examination for different types of culture vessels. This allows the level of the nozzle to be kept constant relative to that of the biological specimen without adjusting the level of the nozzle. 
         [0023]    In the above aspect, the nozzle may be attachably/detachably attached to the main container. 
         [0024]    In this case, it is possible to select and attach/detach a nozzle matching the type of biological specimen incubated and the incubation conditions thereof. 
         [0025]    The present invention provides the advantage of preventing the problem of a specimen being vibrated during supply or drainage of a liquid such as a culture solution, thus allowing acquisition of a stable image. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0026]      FIG. 1  is a longitudinal sectional view showing a culturing system according to an embodiment of the present invention. 
           [0027]      FIG. 2  is a partial longitudinal sectional view showing an example of a nozzle attachment structure of the culturing system in  FIG. 1 . 
           [0028]      FIG. 3  is a longitudinal sectional view showing a first modification of the culturing system in  FIG. 1 . 
           [0029]      FIG. 4  is a longitudinal sectional view showing a second modification of the culturing system in  FIG. 1 . 
           [0030]      FIG. 5  is a longitudinal sectional view showing a third modification of the culturing system in  FIG. 1 . 
           [0031]      FIG. 6  is a longitudinal sectional view showing a fourth modification of the culturing system in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    A culturing system  1  according to an embodiment of the present invention will now be described with reference to  FIGS. 1 and 2 . 
         [0033]    As shown in  FIG. 1 , the culturing system  1  according to this embodiment is mounted on a stage  2  of a microscope and includes a main container  4  accommodating a culture vessel  3  and nozzles  5   a  and  5   b  fixed to the main container  4 . 
         [0034]    The stage  2  of the microscope has a through-hole  2   a  at a position opposite an objective lens  6  disposed therebelow. 
         [0035]    The culture vessel  3 , which is a commercially available glass-bottomed dish, has an opening  3   a  facing upward and a glass slide  3   b  bonded to the underside thereof. A biological specimen A to be incubated, for example, a living cell, is placed on the glass slide  3   b.    
         [0036]    The main container  4  includes a base member  7  mounted on the stage  2  with an opening  7   a  thereof facing upward so as to seal off the through-hole  2   a  of the stage  2  and a lid member  8  disposed so as to seal off the opening  7   a  of the base member  7 . 
         [0037]    In addition, the main container  4  has a temperature-controlling unit, a CO 2 -supplying unit, and a humidity-controlling unit (not shown) so that they can maintain an internal space B, formed by sealing off the top opening  7   a  of the base member  7  with the lid member  8 , at a temperature of, for example, 37° C.±0.5° C., a CO 2  concentration of, for example, 5%±1%, and a humidity of, for example, 95%±5%. 
         [0038]    The base member  7  includes a bottom portion  7   b  mounted on the stage  2  and a peripheral wall  7   c  extending vertically upward from the edges of the bottom portion  7   b.    
         [0039]    A through-hole (transparent portion)  7   d  is provided in the bottom portion  7   b  of the base member  7  at a position where the through-hole  7   d  is sealed off by the underside of the culture vessel  3  after the culture vessel  3  is mounted. 
         [0040]    The lid member  8  has a window portion  8   a  formed of a transparent material such as glass. The window portion  8   a , which is used for transmission observation, transmits illumination light emitted from a light source (not shown) disposed vertically thereabove to illuminate the biological specimen A in the culture vessel  3  so that fluorescence emitted vertically downward from the biological specimen A or transmitted light can be observed through the objective lens  6 . 
         [0041]    In addition, the nozzles  5   a  and  5   b  are fixed to the lid member  8 . The nozzles  5   a  and  5   b , namely, the supply nozzle  5   a  and the suction nozzle  5   b , are disposed under the lid member  8  so as to extend with the ends thereof facing vertically downward. The individual nozzles  5   a  and  5   b , as shown in  FIG. 2 , are attachably/detachably attached by screw fitting to joints  10  that are fixed to the lid member  8  and that are connected to external tubes  9   a  and  9   b.    
         [0042]    When the lid member  8  is disposed at the positron where it seals off the top opening  7   a  of the base member  7  with the two nozzles  5   a  and  5   b  attached to the joints  10 , the nozzles  5   a  and  5   b  are inserted into the culture vessel  3  accommodated in the base member  7  through the top opening  3   a  of the culture vessel  3  and are positioned at predetermined distances from the bottom and side surfaces of the culture vessel  3 . 
         [0043]    The operation of the thus-configured culturing system (incubator)  1  according to this embodiment will be described below. 
         [0044]    To examine the biological specimen A over a long period of time while incubating it in the culturing system according to this embodiment, the culture vessel  3 , which contains the biological specimen A together with a culture solution C, is accommodated in the base member  7  mounted on the stage  2 . The top opening  7   a  of the base member  7  is then sealed off with the lid member  8 , and the inner space B of the main container  4  is maintained at a predetermined incubation environment. The top opening  7   a  of the base member  7  does not necessarily have to be sealed off (in a completely hermetic manner) with the lid member  8  if the entire main container  4  is accommodated in another container maintained at the predetermined environment. 
         [0045]    In this state, the ends of the supply nozzle  5   a  and the suction nozzle  5   b  are inserted into the culture vessel  3  through the opening  3   a  thereof and are positioned in the culture solution C. A pump (not shown) is then driven to supply fresh culture solution C through the supply nozzle  5   a  while draining the old culture solution C by suction through the suction nozzle  5   b.    
         [0046]    For epi-illumination observation, illumination light coming from below the stage  2  through the objective lens  6  passes through the through-hole  2   a  of the stage  2  and the through-hole  7   d  of the base member  7 . The illumination light passes through the glass slide  3   b  at the bottom surface of the culture vessel  3  to irradiate the biological specimen A on the glass slide  3   b . Fluorescence emitted from the biological specimen A passes through the glass slide  3   b  and the through-holes  2   a  and  7   d  and is observed after being collected by the objective lens  6 . 
         [0047]    For transmission illumination observation, on the other hand, illumination light coming from an upper light source enters the main container  4  through the window portion  8   a  to irradiate the biological specimen A through the culture solution C. Of the fluorescence produced in the biological specimen A, the fluorescence traveling downward through the glass slide  3   b  or transmitted light passes through the through-holes  2   a  and  7   d  and is observed after being collected by the objective lens  6 . It is also possible to perform transmission observation using a detector for transmission detection disposed above the biological specimen A by illuminating the biological specimen A from below. 
         [0048]    In this case, because the culturing system  1  according to this embodiment has the nozzles  5   a  and  5   b , for supplying and draining the culture solution C, fixed to the main container  4  without contact with the culture vessel  3 , even if the nozzles  5   a  and  5   b  vibrate due to, for example, pulsations of the pump during the supply or drainage of the culture solution C, the vibrations can be prevented from being transmitted to the culture vessel  3 . This avoids problems such as vibration of the biological specimen A under magnification observation and blurring of the acquired image. 
         [0049]    In this embodiment, additionally, because the nozzles  5   a  and  5   b  are fixed to the lid member  8 , which is separated from the base member  7  in contact with the culture vessel  3 , transmission of vibrations of the lid member  8  to the base member  7  is also inhibited. This advantageously avoids the problem of vibrations of the biological specimen A due to vibrations of the nozzles  5   a  and  5   b  in time-lapse examination, in which changes in the biological specimen A are examined over a long period of time, thus allowing accurate examination with a sharp image. 
         [0050]    In this embodiment, additionally, because the nozzles  5   a  and  5   b  are attachably/detachably attached with the joints  10 , the user can attach nozzles  5   a  and  5   b  of any shape depending on, for example, the type of biological specimen A under examination. For example, attaching tapered nozzles  5   a  and  5   b  minimizes the effect of the surface tension (the surface tension between the nozzles and the culture solution C) of the culture solution C supplied, thus allowing accurate adjustment of the liquid level. 
         [0051]    In addition, long nozzles  5   a  and  5   b  may be used with the ends thereof disposed near the bottom surface of the culture vessel  3  so that the biological specimen A can be examined while being incubated with less culture solution C. This allows efficient utilization of an expensive reagent, for example, one for chemical stimulation. 
         [0052]    Although the lid member  8  has the window portion  8   a  in this embodiment, the window portion  8   a  does not have to be provided if transmission illumination observation is not performed. In addition, although the nozzles  5   a  and  5   b  are attachably/detachably attached, they do not have to be attachable/detachable. 
         [0053]    As shown in  FIG. 3 , additionally, a damper  11  is preferably disposed between the base member  7  and the lid member  8 . The damper  11  is formed of a viscoelastic material such as polyisoprene rubber. The intervening damper  11  absorbs vibrations transmitted from the nozzles  5   a  and  5   b  to the lid member  8  to inhibit transmission of vibrations to the base member  7 , thus further alleviating vibration of the culture vessel  3 . 
         [0054]    As shown in  FIG. 4 , the damper  11  may also be disposed between the joints  10  and the lid member  8 . This inhibits transmission of vibrations from the nozzles  5   a  and  5   b  to the lid member  8 , thus alleviating vibration of the culture vessel  3 . 
         [0055]    As shown in  FIG. 5 , the damper  11  may also be disposed between the bottom portion  7   b  of the base member  7  and the culture vessel  3 . This inhibits transmission of vibrations from the base member  7  to the culture vessel  3  even if vibrations of the nozzles  5   a  and  5   b  are transmitted to the lid member  8  and the base member  7 , thus alleviating vibration of the culture vessel  3 . Naturally, the dampers  11  disposed at the above positions may be used in combination. 
         [0056]    As shown in  FIG. 6 , additionally, a support  12  for the culture vessel  3  may be provided on the bottom portion  7   b  of the base member  7 . The support  12  may be disposed slightly inside the periphery of the culture vessel  3  so as to protrude vertically upward from the bottom portion  7   b  in a rectangular cross section. 
         [0057]    Some types of culture vessel  3 , as shown in  FIG. 6 , have a leg portion  3   c  protruding from the outermost periphery thereof, and the height of the leg portion  3   c  varies depending on the type of culture vessel  3 . Instead of bringing the leg portion  3   c  into contact with the bottom portion  7   b  of the base member  7 , the support  12  can be brought into contact with the underside of the culture vessel  3  to maintain the level of the underside of the culture vessel  3 , that is, the level of the biological specimen A, at substantially the same level irrespective of the type of culture vessel  3 . 
         [0058]    This allows the level of the ends of the nozzles  5   a  and  5   b  to be always kept constant relative to that of the biological specimen A for different types of culture vessel  3 , thus providing identical observation conditions.