Abstract:
The present invention is object to provide a protein chip holding tool that is capable of effectively executing analysis work by preventing protein from being denatured and/or inactivated due to drying while attempting to make the amount of spotting of protein test samples to be spotted on a substrate very slight, and said a chip holding tool comprising a substrate holding member  39  in which at least one or more substrate holding portions  41  holding the substrate  35 , a resilient holding member  45  that covers the upper surface of the substrate holding member  39 , a resilient body engaging portion  51  holding the resilient body  37 , and an opening and closing member  53  that is movably supported on the upper surface of the resilient holding member  45  and opens and closes the openings  45   a.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a protein chip holding tool that is used to produce protein chips by spotting a number of protein test sample solutions on a substrate and to carry out various types of analyses such as solidifying reaction, detection reaction, etc., by distributing a preparation to be tested, on the respective protein test sample solutions of the produced protein chips. 
     BACKGROUND OF THE INVENTION 
     For example, when carrying out various types of protein analyses such as protein screening, quantitative analysis, etc., like a blood test in clinical fields, a protein test sample solution is distributed into respective holes of a microtiter plate (80 mm wide×120 mm long, 96 holes or 384 holes), and protein chips are prepared. After that, a solution of a preparation to be tested is distributed into the respective holes of the protein chips, whereby the preparation to be tested is analyzed by a solidification reaction and a detection reaction. 
     Recently, in order to efficiently analyze a number of test samples to be tested in analysis work at a time and to reduce the number of consuming test samples in protein analysis and oligonucleotide (DNA, RNA) analysis, a great number of test samples are spotted on a single substrate at a high density. Resultantly, test samples to be spotted are made very slight in order of microliter or nanoliter per spot. 
     However, as regards protein test samples, where the spotting amount is made very slight as described above, the protein test samples are dried in a very short time, and the protein itself is denatured and is inactivated, wherein there is a problem in that the analysis work is disabled. Therefore, it is necessary to increase the number of spots while preventing the protein from being denatured and/or inactivated due to drying when producing protein chips. 
     The present invention has been developed so as to solve the problems in the prior arts, and it is therefore an object of the invention to provide a protein chip holding tool that is capable of effectively executing analysis work by preventing protein from being denatured and/or inactivated due to drying while attempting to make the amount of spotting of protein test samples to be spotted on a substrate very slight as described above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an entire perspective view of a protein chip holding tool; 
         FIG. 2  is an entire front elevational view of a unit for spotting a protein test sample solution; 
         FIG. 3  is a perspective view showing a state where a resilient layer retaining member of the protein chip holding tool is released; 
         FIG. 4  is a longitudinally sectional view taken along the line A—A in  FIG. 1 ; 
         FIG. 5  is a longitudinally sectional view taken along the line B—B in  FIG. 1 ; 
         FIG. 6  is a view explaining another example of a supporting structure of a slide shutter; 
         FIG. 7  is a view explaining still another example of the supporting structure of the slide shutter; 
         FIG. 8  is a view explaining a pressing structure effected by a locking member; 
         FIG. 9  is a view showing a state where a substrate and a resilient layer are set on the protein chip holding tool; 
         FIG. 10  is a view showing a closed state of the resilient layer retaining member; and 
         FIG. 11  is a view showing an open state of holes in the resilient layer holding member. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a description is given of embodiments of the invention with reference to the accompanying drawings. 
     In  FIG. 1  through  FIG. 7 , a unit  1  for spotting a protein test sample solution is composed of the suction and discharge unit  3  and a distributing unit  5 , and a protein chip holding tool  7  according to the invention is fixedly or detachably attached to distribution points of the distributing unit  5 . 
     First, a description is given of the unit  1  for spotting a protein test sample solution that is used to produce protein chips and to react the same with preparations to be tested. 
     The suction and discharge unit  3  is disposed on the illustrated right side of the body frame  9  of the unit  1  for spotting a protein test sample solution, and a moving body  11  of the suction and discharge unit  3  is caused to reciprocate in the three-dimensional directions by an X-axis drive mechanism, a Y-axis drive mechanism and a Z-axis drive mechanism (neither of these illustrated). 
     The above-described drive mechanisms of respective axes can be composed of a feed-screw drive mechanism that is constructed of a feed screw coupled to a servo motor and a nut secured on a moving body on the respective axes, a belt drive mechanism in which a part of a belt applied to a pair of rotary bodies, one of which is coupled to a servo motor, is fixed on a moving body on the respective axes, or a linear motor in which a servo motor is composed of a stator and a mover secured on the moving body. 
     A number of suction needles  13  each having an axial line in the up and down direction, are disposed to be in a matrix form of, for example, 8×12 at appointed spacing in both the X-axis and Y-axis directions. The respective suction needles  13  are faced to respective reservoirs (neither of these illustrated) of a container body placed on the body frame  9 . The same type or different types of protein test sample solutions, which are spotted on a substrate  35  of a protein chip  33 , described later, which is about to be produced, and solutions of preparations to be tested, which are caused to be reacted with the protein test samples to be spotted on the protein chips  33  are accommodated in the respective reservoirs of the corresponding container body. 
     The base end portions of the respective suction needles  13  are connected to a suction and discharge changer device  17  via a pipe  18 . The suction and discharge changer device  17  is composed of a fixing board (not illustrated) in which a plurality of suction portions and discharge portions that are coincident with the number of suction needles  13  are provided adjacent to each other, and a changer board (not illustrated), which is provided with a suction and discharge portion that is supported so as to move over a distance equivalent to an arrangement interval of the suction portion and discharge portion in an airtight state with respect to the corresponding fixing board, and that selectively communicates with the respective suction portions and discharge portions. 
     And, the end portion of the pipe  18  connected to the suction needle  13  is connected to the suction portion of the fixing board. Also, the end portion of a pipe  23 , which is connected to the distribution device  5  described later, is connected to the discharge portion. Also, the end portion of a pipe  27  that is connected to a suction and discharge device  25  is connected to the suction and discharge portion of the changer board. 
     The suction and discharge device  25  is composed of syringes  25   a  whose quantity is equivalent to, for example, the number of suction needles  13 , a protein test sample solution and a preparation solution to be tested, which are reserved in respective reservoirs, are sucked into syringes  25   a  in line with reciprocation of a piston, and at the same time the sucked protein test sample solution and preparation solution are discharged to a distribution device  5 . The amount of suction of the protein test sample solution and preparation solution and the amount of discharge thereof are adequately established by a stroke movement of the piston. The stroke of the piston may be established so that the amount of discharge of the protein test sample solution and preparation solution with the distribution device  5  are caused to become, for example, 0.5 through 10 μl, preferably 5 μl. 
     Further, the protein test sample solution and preparation solution to be tested is made into a solution in which protein and a preparation to be tested, which reacts therewith, are dissolved in, for example, PBS (0.14M sodium chloride, and 0.01M phosphate buffer solution, whose pH has been adjusted to 7.2). 
     The distribution device  5  is disposed at the left side of the illustrated body frame  9 . A moving body  29  of the corresponding distribution device  5  is controlled so as to move in three-dimensional directions by drive mechanisms (all of which are not illustrated) similar to the X-axis, Y-axis and Z-axis drive mechanisms of the suction and discharge device  3 . 
     The underside of the moving body  29  has an axial line in the up and down direction, and is provided with a number of distribution needles  31 , which are disposed in 8-by-12 matrices with spacing of approx. 100 through 1000 μm in, for example, the X-axis and Y-axis directions. The respective distribution needles  31  have a diameter of 500 through 2000 μm at their tip end sides, and pipes  23  are connected to the respective base end portions. 
     The tip end parts of the respective distribution needles  31  are selectively faced to a number of protein chips  33  that are set in a protein chip holding tool  7  secured at the distribution device  5 . 
     The respective protein chips  33  have a structure in which a silicone rubber made resilient layer  37  is laminated on a substrate  35  such as slide glass, a plastic plate, etc., made of polyethylene, polypropylene, etc. Holes  37   a , whose number is coincident with the number of distribution needles  31 , having the same matrices (8-by-12 matrices) as those of the distribution needles  31  are formed on the resilient layer  37 , and the plane facing the substrate  35  is ground and flattened, thereby securing satisfactory contacting ability with the substrate  35 . 
     Next, a description is given of the protein chip holding tool  7 . 
     A base plate  39  holds five substrates  35 , for example, as shown in  FIG. 9 . On the upper plane of the base plate  39 , downward facing recesses  41  which are shaped so as to be coincident with the respective substrates  35  are provided with adequate spacing in the lengthwise direction of the base plate  39 , and the substrates  35  are held in the respective downward facing recesses  41 . 
     Notched parts  43  are formed in the base plate  39  such that a finger, for example, may be inserted into the respective notched parts  43 , thereby enabling removal of the substrates  35  held in the downward facing recesses  41 . 
     A lid  45  that constitutes a resilient layer holding member is supported at the left side end part, of the base plate  39  as shown in  FIGS. 3 and 9  so that the lid  45  moves and turns between the position covering the upper surface of the base plate  39  and the position separated therefrom. 
     Upward facing recesses  51  that are sized to be coincident with the downward facing recesses  41  are formed on the bottom (the plane facing the base plate  39 ) of the lid  45  so that these recesses  51  are faced to the respective downward facing recesses  41 . And the resilient layers  37  that constitute parts of the protein chips  33  are held in the upward facing recesses  51 . 
     A number of holes  45   a  that function as openings are provided in the lid  45 , in areas corresponding to the upward facing recesses  51 , so as to be coincident with the respective holes  37   a  in the resilient layers  37  that are retained in the respective upward facing recesses  51 . 
     A slide shutter  53  is supported on the upper surface of the lid  45  so as to be movable in the left and right direction shown in the  FIG. 4  over approximately half of the distance between the holes  45   a  in the left and right direction of  FIG. 4 . A number of slits  53   a  are formed in the slide shutter  53  so as to become coincident with the respective holes  45   a  when the slits  53   a  are moved to the left side, as shown in  FIG. 4 , on the lid  45 . The slide shutter  53  locates the respective slits  53   a  between the respective holes  45   a  to close the holes when the slide shutter  53  is moved to the right side with respect to the lid  45 . The slide shutter  53  exposes the respective boles  37   a  of the resilient layers  37  to the outside via the slits  53   a  and respective holes  45   a  when the slits  53   a  are positioned over the holes  45   a.    
     The structure for supporting the slide shutter  53  with respect to the lid  45  may be a structure for slidably supporting the end part of the slide shutter  53  on a supporting plate  54  secured at both ends of the lid  45  in the lengthwise direction thereof as shown in  FIG. 1 . Alternatively, the respective end portions of the slide shutter  53  in the lengthwise direction may be folded to be like an inverted C shape with regard to the cross section thereof and the end portions may be slidably engaged with the respective end portions of the lid  45  and support the same as shown in  FIG. 6 . Alternatively, slits  53   b  having a length coincident with the moving amount of the slide shutter  53  may be formed on the respective end portions of the slide shutter  53  in the lengthwise direction as shown in  FIG. 7 , and engaging members  53   c  such as stepped axes and stepped screws, etc., may be inserted into the respective slits  53   b , so that the slide shutter  53  is slidably supported at the lid  45 . 
     An operating arm  55  having an engaging hole  55   a  is formed so as to protrude outward at the respective forward and backward end portions at the right side, as shown in  FIG. 9 , of the slide shutter  53 . An operating member  57 , such as an electromagnetic solenoid and a pneumatic cylinder, is attached to the respective forward and backward end portions, as shown in  FIG. 9 , of the base plate  39 . An engaging portion  57   a  of each operation member  57  is engaged with the respective engaging hole  55   a , such that the slide shutter  53  is opened and closed with respect to the lid  45  by actuation of the corresponding operating member  57 . 
     A locking member  59  at the right side, as shown in  FIG. 10 , of the base plate  39  is supported so as to be turnable. The locking member  59  is composed of a locking arm portion  59   a , which is brought into contact with the entirety of the right end portion of the lid  45 , in the lengthwise direction of the lid  45 , when the lid  45  turned to the position covering the upper surface of the base plate  39  and an axial supporting arm portion  59   b , which suspends extends from both end parts of the locking arm portion  59   a  and is axially supported on the base plate  39 . When the locking arm portion  59   a  is brought into contact with the upper surface at the right side end of the lid  45  and locked thereat, the axial supporting member  59  causes the respective resilient layers  37 , which are held on the lid  45 , to be adhered to the respective substrates  35 , which are retained on the base plate  39 . 
     Where the length of the axial supporting arm portion  59   b  is made short to cause the locking member  59  to be tightly adhered to the lid  45 , maneuverability is worsened when locking and unlocking the locking arm portion  59   a . To prevent the above from occurring, as shown in  FIG. 8 , a pressing member  61  such as a plate spring or a pin having a spring, etc., is provided at the locking arm portion  59   a , and the lid  45  is pressed in the closing direction by a resilient force of the corresponding pressing member  61 , wherein the adhesivity between the substrate  35  and the resilient layer  37  may be increased. 
     Next, a description is given of an embodiment using a protein chip holding tool  7  when producing a protein chip  33  and when analyzing a preparation to be tested, by using the produced protein chip  33 . 
     First, a description is given of an example using the protein chip holding tool  7  when producing a protein chip  33 . 
     Prior to producing the protein chips  33 , the moving body  11  is controlled and moved in a state where the respective suction needles  13  are caused to communicate with the respective syringes  25   a  of the suction and discharge device  25  by the suction and discharge changer device  17 , and a number of suction needles  13  are caused to sink into respective reservoirs of a container body in which a protein test sample solution is accumulated. After that, a piston is driven in the suction direction, wherein the protein test sample solution is sucked into the syringes  25   a  and is accumulated therein. The changer plate  21  of the suction and discharge changer device  17  is moved after the above-described suction action is carried out, wherein a flow channel is changed over so that the respective syringes  25   a  of the suction and discharge device  25  communicates with the respective distribution needles  31 . 
     On the other hand, in a state where the lid  45  is moved and turned to an open position with respect to the base plate  39  as shown in  FIG. 9 , substrates  35  are set in respective downward facing recesses  41  of the base plate  39  and resilient layers  37  are set in respective upward facing recesses  51  of the lid  45 . After that, the lid  45  is turned and moved to the base plate  39  side as shown in  FIG. 1 , and the locking member  59  is locked at the tip end portion of the lid  45 . 
     At this time, the resilient layers  37  are resiliently deformed by locking of the locking member  59  and are brought into close contact with the substrates  35 . Further, the engaging portions  57   a  of the operating members  57  are engaged in the engaging holes  55   a  in the above-described closed state. Also, as shown in  FIG. 10 , the slide shutter  53  is slid on the upper surface of the lid  45 , such that the respective slits  53   a  are located between the holes  45   a , and the respective holes  37   a  are closed. 
     The slide shutter  53  is slid in the leftward direction shown in, for example,  FIG. 11 , by actuating the operating member  57  in the above described state, and the respective slits  53   a  are made coincident with the respective holes  45   a  of the lid  45 , such that the respective holes  37   a  of the resilient layers  37  are exposed to the outside. 
     After, in the above-described state, the respective distribution needles  31  are caused to face the respective exposed holes  37   a  of the resilient layers  37  secured in the first row in the forward and backward direction via the slits  53   a  and holes  45   a  by controlling and moving the moving body  29 , the moving body  29  is lowered, and the tip end parts of the respective distribution needles  31  are caused to advance into the respective holes  37   a . Thereafter, the pistons in the respective syringes  25   a  are slightly moved in the micron level, whereby the protein test sample solution accumulated in the syringes  25   a  is discharged to the respective distribution needle  31  side and is dispersed into the respective holes  37   a.    
     At this time, the amount of movement of the pistons in the syringes  25   a  is controlled so that the amount of protein test sample solution accumulated in the holes  37   a  becomes 0.5 through 10 μl, preferably 5 μl. Also, since the resilient layers  37  are brought into close contact with the upper surfaces of the substrates  35  at a high degree of airtightness as described above, the protein test sample solution accumulated in the holes  37   a  is prevented from leaking, whereby respective protein test sample solutions accumulated in the respective holes  37   a  are prevented from contaminating each other. 
     Next, the moving body  29  is moved in the forward and backward direction after the respective distribution needles  31  are removed from the holes  37   a  of the resilient layer  37  at the first row in the forward and backward direction by vertically moving the moving body  29 , and the moving body  29  is caused to face the respective holes  37   a  of the resilient layer  31  at the second row in the forward and backward direction. After that, an appointed amount of protein test sample solution is distributed into the respective holes  37   a  of the resilient layer  37  at the second row in the forward and backward direction by actions similar to those described above. 
     By repeating the above-described actions, an appointed amount of a protein test sample solution is distributed into the holes  37   a  of the respective resilient layers  37  closely adhered to the respective substrates  35 , and five protein chips  33  are produced. After that, the slide shutter  53  is moved in the rightward direction in  FIG. 9  by moving the operating member  57  back, wherein the respective slits  53   a  are located between the respective holes  45   a , and the respective holes  37   a  are closed. 
     Thereby, it is possible to prevent the protein of the protein test sample solutions accumulated in the respective holes  37   a  of the resilient layers  37  in the protein chips  33  from being denatured due to drying in a short time and being inactivated, whereby it is possible to produce protein chips  33  by which a reaction of a preparation to be tested in a liquid phase can be securely carried out. 
     Next, a description is given of a holding state of protein chips by a protein chip holding tool  7  when a reaction with the preparation to be tested is carried out. 
     A number of suction needles  13 , a suction and discharge changer device  17 , a suction and delivery device  25 , distribution needles  31 , which are used to produce protein chips  33 , and the inside of pipes  18 ,  23  and  27  that connect the above components are washed prior to the distribution of a preparation to be tested, to protein test samples in the protein chips  33 . 
     A method for washing protein test samples is such that the suction and discharge device  25  is actuated while varying respective flow lines by the suction and discharge changer device  17  in a state where collection containers (not illustrated) are respectively placed on the body frame  9  responsive to the suction and discharge device  3  and distribution device  5 , and excessive protein test sample solutions in the suction needles  13 , suction and discharge changer device  17 , suction and discharge device  25 , distribution needles  31 , and pipes  18 ,  23  and  27 , which connect the above components, are respectively discharged from the respective suction needles  13  and distribution needles  31  into the respective collection containers for collection thereof. 
     Next, the suction and discharge device  25  is actuated for suction in a state where the respective distribution needles  31  are immersed in a washing solution container (not illustrated) that is placed on the body frame  9  at the suction and discharge device  3  side, and the washing solution is sucked into the respective syringes  25   a . After that, the suction and discharge device  25  is actuated for discharge in a state where the flow lines are changed by the suction and discharge changer device  17  to the suction needle  13  side and the distribution needle  31  side in order, wherein work of discharging the accumulated washing solution from the respective suction needles  13  or distribution needles  31  into the collection containers is repeated several times, thereby washing the protein test sample solution. 
     A washing solution used for the above-described washing contains a 0.005 through 0.1% Tween 20 water solution, ultra-pure water, and PBS. The protein test sample solutions are washed off by using the above-described 0.005 through 0.1% Tween 20 water solution, ultra-pure water, and PBS in order. After that, the pistons of the respective syringes  25   a  of the suction and discharge device  25  are actuated for operation to discharge internal air contained in the respective suction needles  13  and distribution needles  31  therefrom, wherein these suction needles  13 , suction and discharge changer device  17  and distribution needles  31 , and the inside of pipes  18 ,  23  and  27  that connect the above-described components are dried. 
     After the above-described washing treatment is completed, a container body in which a preparation solution to be tested, and which will be analyzed, is accumulated in its respective reservoirs, is set on the body frame  9  at the suction and discharge device  3  side. After that, the moving body  11  is controlled and moved as in the case where the protein chips  33  are produced, the respective pistons of the suction and discharge device  25  are actuated for suction after the respective suction needles  13  are immersed in the respective reservoirs of the container body in which a preparation solution to be tested is accumulated, whereby the preparation solution is sucked into syringes  25   a  and accumulated therein. 
     After the above-described sucking operation is completed, the changer board  21  of the suction and discharge changer device  17  is moved and the flow line is changed so that the respective syringes  25   a  of the suction and discharge device  25  are able to communicate with the respective distribution needles  31 . After that, the moving body  29  is controlled and moved, whereby the respective distribution needles  31  are respectively faced to the respective holes  37   a  of the resilient layers  37  at the protein chips  33  that are held by the protein chip holding tool  7 , for example, at the first row in the forward and backward direction. 
     At this time, the slide shutter  53  is moved by operating the operating member  57  to cause the holes  37   a  of the resilient layers  37  of the respectively produced protein chips  33  to be exposed to the outside. 
     Next, after the moving body  29  is moved downward in the above-described state, and the respective distribution needles  31  are caused to advance into the respective holes  37   a , the respective pistons of the suction and discharge device  25  are moved by an appointed distance in the discharge direction, and the preparation solution to be tested, which is accumulated in syringes  25   a , is discharged by an appointed amount. 
     After, by repeating the above-described action, the preparation solution to be tested is discharged, at an appointed ratio of amount, into the holes  37   a  of the resilient layers  37  at the respective protein chips  33  that are set on the protein chip holding tool  7 , the operating member  57  is moved back in order to slide the slide shutter  53  into the closing direction, wherein the respective holes  37   a  of the resilient layers  37  are closed, and the protein test samples, which are in the holes  37   a  of the respective resilient layers  37 , and a preparation solution to be tested, are reacted in the liquid phase in the above-described state. 
     In the above described reaction, since the respective holes  37   a  of the resilient layers  37  are interrupted by the atmosphere by the slide shutter  53 , the protein test sample solutions, which are accumulated in the respective holes  37   a , and the preparation solutions are prevented from being dried, wherein it is possible to securely carry out a liquid phase reaction. 
     The protein chip holding tool  7  has the following actions and effects.
     1. By operating to close the lid  45 , in which the resilient layers  37  are set, with respect to the base plate  39  on which the substrates  35  are set, it is possible to bring the resilient layers  37  and the substrates  35  into close contact with each other. At this time, the adhesivity of both can be increased by resiliently deforming the resilient layers  37  with respect to the substrates  35 , wherein it is possible to prevent the protein test sample solutions distributed in respective holes  37   a  of the resilient layers  37  and a preparation solution to be tested from leaking, and it is possible to prevent both of the solutions from contaminating each other.   2. Since the matching planes of the resilient layers  37  and the substrates  35  are polished and flattened at a high degree of accuracy, the adhesivity of both can be increased, and it is possible to prevent the protein test sample solutions distributed in respective holes  37   a  and a preparation solution to be tested from leaking, and it is possible to prevent both of the solutions from contaminating each other.   3. By sliding the slide shutter  53  to expose the respective holes  37   a  of the resilient layers  37  when producing protein chips and analyzing a preparation to be tested by the produced protein chips, it becomes possible to distribute the protein test sample solutions and preparation solution to be tested, and it is possible to prevent the protein test samples and preparation solution to be tested from being denatured or inactivated due to drying of the distributed protein test samples and the preparation solution, which is added thereto, by closing the holes  37   a  of the resilient layers  37  by causing the sliding shutter  53  to slide after the protein chips are produced or when executing a reaction. That is, analysis of the preparation solutions to be tested can be effectively carried out.   4. Since the lid  45  is pressed to the base plate  39  side by the pressing member  61  of the locking member  59  and the resilient layers  37  are brought into close contact with the substrates  35  at a high degree of airtightness, it is possible to prevent protein test sample solutions, which are distributed into the respective holes  37   a , and a preparation solution to be tested from leaking, and it is also possible to prevent the solutions from contaminating each other.   

     The present invention may be carried out in the following modified versions.
     1. Although, in the above description a structure is described in which five substrates  35  are set on a single base plate  39 , a plurality of lines of substrates, each line consisting of five substrates, may be set In this case, a lid may be provided with slide shutter secured per line, and a locking member  59 .   2. Although, in the above description a structure is described in which a number of holes  45   a  coincident with the number of holes  37   a  of the held resilient layers  37  are provided in the lid  45 , a plurality of slits having a length coincident with the entirety of a plurality of holes  37   a  in the row direction of a resilient layer  37  may be employed. Also, slits  53   a  of the slide shutter  53  may be made into holes coincident with the number of holes  37   a  of the resilient layers  37 .   3. Although, in the above description, the slide shutter  53  is selectively slid by the operating member  57  and the holes  37   a  of the resilient layers  37  are opened and closed, the operating member  57  is not necessarily requisite in the composition of the present invention. Instead, an operator may manually slide the slide shutter  53 .   4. Although, in the above description a structure is described in which the slide shutter  53  is opened and closed by normal and reverse operations of the operating member  57 , another structure may be employed, in which a tension spring or a compression spring is provided at the lid  45  and the slide shutter  53 . In this case, the slide shutter  53  is slid in the opening direction by the operating member to open the holes  37   a  while the slide shutter  53  is always urged to slide in the closing direction by a resilient force of these spring members with respect to the lid  45 .