Abstract:
The invention relates to a transport container ( 1 ) comprising a superinsulation in the form of an evacuated insulating container ( 2 ) comprising a vacuum maintaining material ( 55 ). The transport container is provided with a cooling container ( 16 ) comprising a heat-conducting metal wool filling ( 57 ) and an organic coolant which undergoes a solid/liquid phase change in the temperature range of between −30° C. and −850° C. and has a heat of fusion of at least 50 J/ml. A slim cylindrical sample chamber ( 24 ) is used to receive deep-frozen tissue samples ( 26 ), said chamber being surrounded by the cooling container ( 16 ) and merging into a long neck opening ( 25 ) forming a single component therewith, said opening being largely filled by the insulating shaft ( 30 ) of a screwable plug ( 28 ) and sealed from the sample chamber ( 24 ). The air in the ring gap ( 32 ) created can be evacuated by means of an evacuating system ( 48 ). The plug ( 28 ) is provided with a stopper ( 38 ) protruding into the sample chamber ( 24 ) and a data logger ( 41 ) for recording the temperature in the sample chamber ( 24 ). Following the freezing of the coolant, the transport container ( 1 ) enables distribution times and intermediate storage of up to 14 days without any risk of damage to the tissue samples ( 26 ) received therein.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
     This U.S. patent application contains some subject matter which is similar to some subject matter of U.S. patent application Ser. No. 10/585,378, filed on Apr. 6, 2007. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a transport container for maintaining the temperature of frozen goods, in particular frozen biological tissue samples or cell cultures. 
     Clinical diagnostics and research often require quick analysis of tissue samples in external specialist laboratories in order to obtain results for a decision regarding therapy. The analysis methods used (e.g. RNA analyses, protein markers) are rapidly developing. Deep freezing a sample has proven to destroy the least amount of information contained therein. Since research leads to the discovery of new markers on an almost daily basis, conserving the information is important, and it makes sense not only to subject the sample to the currently available examinations but also to conserve the samples as permanently as possible by deep freezing. Should the patient develop a problem in the months or even years after the sample was taken, e.g. suffer a relapse and require therapy, renewed examination of the original sample using analysis methods which may still have been unknown when the sample was taken could be of assistance and could indicate a promising targeted, expensive modern therapy in place of an untargeted standard therapy, and justify this financially to the benefactors. 
     Hence, it is important to have a transport container for sending frozen individual samples and which reliably avoids a transport-dependent break of the closed freezing chain while having a design which is as small and light as possible, which satisfies existing regulations, and keeps the sending costs low. Although the complexity and costs of sending can be reduced to a certain extent by collecting samples and sending them together, with a collection period of at most five days being feasible, this does however lead to administrative and logistical complexities, with intermediate storage of the samples at very low temperatures becoming necessary. Only a very small number of hospitals have a chest freezer required for this purpose, which can cool down to −70° C. for example. 
     WO 2005/066 559 A2 has already disclosed a transport container for maintaining the temperature of frozen biological tissue samples and cell cultures. It comprises an insulation container which is accessible via an insulating cover part and has superinsulation with a thermal conductivity λ≦0.002 W/(mK). A cooling container comprising a coolant chamber is provided in the insulation container, which coolant chamber surrounds a sample chamber for the frozen goods except for an access opening on the fastener side; the coolant chamber is permanently hermetically sealed, and comprises a coolant which emits the cold by solid/liquid phase transition. The coolant undergoes phase transition in the temperature range between −15° and −100° C., in particular between −30° and −85° C. and has a heat of fusion of at least 50 J/ml. 
     The cooling container with the coolant chamber and the sample chamber can be removed from the insulation container in this known transport container. The sample chamber extends almost to the upper end of the cooling container. The metallic inner wall of the insulation container merges into the outer wall and there is metallic contact between them. 
     This known embodiment already affords the possibility of maintaining the temperature of frozen samples for a number of days by using a coolant with a high heat of fusion and by means of the superinsulation with low thermal conductivity; however, the prescribed stringent requirements cannot always be reliably fulfilled because thermal bridges are present, as a result of which the coolant can be exhausted prematurely due to the detrimental influx of heat, and hence this can lead to a loss of information in the sample. Moreover, it was found that the handling of the known transport container is not yet ideal. 
     SUMMARY OF THE INVENTION 
     Accordingly, the invention is based on the object of developing a transport container which is improved with regard to its functionality and handling, ensures a reliable deep-frozen state during storage and transport, completely satisfies the existing transport regulations for frozen biological material, and can be produced without problems. 
     Using the known transport container described above as a starting point, according to the invention, this object is achieved by virtue of the fact that the cooling container comprising the coolant chamber is fixedly integrated in the insulation container; that the insulation container extends beyond the sample chamber by a length which exceeds its transverse dimensions by at least a factor of three by forming a neck-shaped opening; that on the outer end of the neck opening, provision is made for an insulation ring, which insulates the inner wall and the outer wall of the insulation container from each other, and elastically mounts the inner wall with the connected cooling container with respect to the outer wall, a plug being assigned to the cover part and which extends into the neck opening with an insulation shaft, fills the neck opening substantially over its entire length, and is sealed from the inner wall of the insulation container on the protruding end by means of a neck seal; and that a container seal is arranged between the insulation container and the cover part, an evacuation apparatus being provided for evacuating the cover interior, including the neck opening gap surrounding the insulation shaft. 
     Thermal bridges in the region of the access to the sample chamber can be reliably avoided by means of these measures so that a particularly good performance with a long-lasting cooling effect can be achieved. A thermally conducting, metallic connection between the inner wall and the outer wall of the insulation container is avoided by means of the insulation ring, with an influx of heat into the sample chamber through the inner wall being further reduced by means of the long neck opening. Additionally, despite the weight of the cooling container with the coolant hanging on the inner wall, the latter can be designed to be thin due to its elastic mounting, and hence the conduction cross section can be further reduced. Integrating the cooling container furthermore makes a relatively narrow neck opening possible, which likewise reduces the heat conducting inner wall cross section. In addition, heat input due to convection of the air in the cover interior and within the adjacent neck opening is counteracted by only a narrow neck opening gap remaining as a result of the plug with the insulation shaft and, moreover, it being possible to evacuate the trapped quantity of air. 
     If the entire insulation container were to be produced from plastics with low thermal conductivity to avoid the thermal bridge between inner wall and outer wall of the insulation container, this would have the disadvantage that said plastic has to be not only resistant against the (organic) coolant, but additionally has to be stable at very low temperatures and highly vacuum-tight. This also means that neither organic degassing of the plastic itself, nor diffusion of the coolant is permitted. This dilemma cannot be solved by installing a separate coolant container made of metal into the plastic container either, because in that case a gap is created between the sample chamber and the neck which is no longer accessible in everyday use. However, due to existing transport regulations for biological samples and tissue samples, and for reasons of hygiene, the sample space must be self-contained and easy to clean should the transport container be reused. For this reason, it is expedient to fixedly integrate the cooling container into the insulation container and to make the wall of the sample chamber and the neck opening, together with the inner wall of the cooling container, from one piece, for example from stainless steel, and thus obtain a seamless sample chamber. In this case, the metallic inner wall additionally has the advantage of an improved heat transfer during the cold-loading prior to the use of the container, that is to say during the transition of the liquid coolant into the solid phase. 
     The transport container according to the invention permits a cooling duration of approximately 14 days after cold-loading with complete transition of the coolant into the solid state, and hence permits cold-loading by the supplier, and a “ready to use” system, in which the customer, e.g. a hospital, is supplied with ready-for-use transport containers, which are sent to the customer by the supplier with the required reliability, can be intermediately stored by the customer for up to a week, and can then be sent to a central laboratory by the customer. 
     Expedient refinements and developments of the invention emerge from the dependent claims. These also relate to expedient measures in conjunction with the cold-loading, and will be addressed in the following description of the figures. 
     The transport container according to the invention and its production, as well as cold transfer devices assigned to the transport container for cold-loading are described in more detail below in an exemplary manner on the basis of schematic drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a section through the container axis of a transport container with three samples; 
         FIG. 2  shows the transport container in accordance with  FIG. 1 , with an outer container serving as an outer packaging, in a reduced scale and also in a sectional view; 
         FIG. 3  shows a further-reduced cross section of the outer container in accordance with  FIG. 2 ; 
         FIGS. 4 to 7  show, in vertical sections, production steps during the assembly of the cooling container and its connection to the inner wall of the insulation container; 
         FIG. 8  shows a vertical section of filling the cooling container with the coolant through a filling opening; 
         FIG. 8   a  shows a detail enlargement from  FIG. 8  after the filling opening has been hermetically sealed; 
         FIGS. 9 to 12  show, in vertical sections, the further assembly of the insulation container while integrating the cooling container; 
         FIG. 13  shows, in a vertical section, the cover part of the insulation container with indicated installation of an evacuation valve; 
         FIG. 14  shows, in an enlarged scale and partly in a vertical section, the plug, provided in accordance with  FIG. 1 , which is installed into the neck opening before the cover part is put on; 
         FIG. 15  shows, in a vertical section, the direct cold-loading of the transport container with liquid nitrogen; 
         FIG. 16  shows a cold-loading apparatus for indirect cold-loading of the transport container with liquid nitrogen using an upwardly extending cooling finger; 
         FIG. 17  shows the cold-loading by means of a cooling finger by using a different cold source; 
         FIG. 18  shows a cold transfer device with an upwardly extending cooling finger to be arranged in a freezer room; 
         FIG. 19  shows a plan view of the cold transfer device in accordance with  FIG. 19  comprising lamellae and an upwardly extending cooling finger; 
         FIG. 20  shows, in a vertical section, the assembly of the transport container ready to be sent after cold-loading; and 
         FIG. 21  shows the opening, filling and resealing of the transport container at a decentralized location where the samples accumulate. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The transport container  1 , drawn in an upright position in  FIG. 1 , comprises an approximately cup-shaped insulation container  2  with an inner wall  3  and an outer wall  4 , as well as an inner base  5  and an outer base  6 . The outer base  6  (as is also explained in  FIG. 11 ) is plugged onto the slightly retracted lower end of the outer wall  4  and adhesively bonded or soldered onto the latter. 
     At the upper end, the outer wall merges into an interior flange  7 , which comprises an annular groove  8  for holding a container seal  9  and which merges into a downwardly extending, peripheral connection web  10 . 
     The inner wall  3 , produced from thin-walled stainless steel, is designed to be thin like a pipe and is provided at its lower end with a chamber base  11 ; it has a beaded constriction  12  at medium height, supports a female thread  13  at its upper end, and merges directly above this into an outwardly protruding annular flange  14 . 
     An insulation ring  15  is provided at the upper end of the insulation container  2 , by means of which ring the annular flange  14  of the inner wall  3  and the connection web  10  of the outer wall  4  are fixedly adhesively bonded to one another at a distance, as can be seen in  FIGS. 10 and 11  as well. In this fashion there is a stretch of insulation between the metallic walls  3  and  4  of the insulation container  2 . The insulation ring  15 , adhesively bonded in-between, at the same time effects an elastic mounting of the inner wall  3  with respect to the outer wall  4  in the manner of a silent block. 
     An annular cooling container  16  is fixedly integrated into the insulation container  2  and it has a peripheral wall  17 , which merges at its upper end into a cover flange  18  with an upwardly extending inner web  19 . The cooling container  16  is integrated into the insulation container in such a way that the former&#39;s inner peripheral wall  20  is formed by the lower half of the inner wall  3 , while the inner base  5  and the chamber base  11  form the flat central region of the coolant chamber  21 . A central weld spot  22  between the inner base  5  and the chamber base  11  reduces possible mechanical loads in the upper region of the inner wall  3 . The inner web  18  of the cooling container  16  is fixedly connected to the inner wall  3  by means of a welding bead  23 , and as a result of this the coolant chamber  21  is hermetically sealed. 
     The constriction  12  of the inner wall  3  subdivides the space within the inner wall  3  into a lower sample chamber  24  and an upper neck opening  25  ( FIG. 5 ). The sample chamber  24  can, as illustrated, simultaneously hold three different samples  26  in respectively one sample container  27 , which samples can be Nunk tubes, for example. 
     A plug  28  is installed in the neck opening  25 , which is illustrated in an enlarged form in  FIG. 14 . In the vertical section, the plug  28  is T-shaped with an upper head  29  having an increased width and a central insulating shaft  30 , which extends downward and has a male thread  31  on its upper end. By means of this, the plug  28  is screwed into the female thread  13  of the inner wall  3 . In this case, the length of the insulation shaft  30  corresponds to the height of the neck opening  25  so that only an annular gap  32  of the latter remains free. On its lower end, the insulation shaft  30  carries an annular neck seal  33 , which, when the plug  28  is screwed in, is pushed against the valve seat  34  ( FIG. 20 ) which is formed by the constriction  12  on the inner side of the inner wall  3 , and thus seals the sample chamber  24  with respect to the neck opening  25  or the annular gap  32 . This annular gap  32  is subdivided into sections by O-rings  35  which are inserted into annular grooves  36  of the insulation shaft  30 . This counteracts heat transmission through the annular gap  32  due to convection. A longitudinal groove  37  ( FIG. 14 ) in the insulation shaft  30  extends beyond the O-rings  35  and the male thread  31 , and ensures pressure balance between the gap sections and the upper side of the plug  28 . 
     The insulation shaft  30  carries a protruding pad  38  on its underside, which pad  38  is used to absorb sample liquids, which may be leaking, and can easily be replaced. Cavities  39  are provided in the head  29  which are accessible from above and covered by cavity covers  40 . By way of example, the cavities  39  can accommodate a data logger  41  and a battery  42  associated with it. The data logger  41  is connected to a temperature sensor  44  at the lower end of the insulation shaft  30  via a signal line  43 , which is molded-in in a vacuum-tight fashion, so that the temperature prevailing in the sample chamber  24  can be continuously recorded. As an alternative, provision can be made for a simplified plug without data logger, battery and temperature sensor. 
     The insulation container  2  is covered by a heat-insulating cover part  45 , on whose underside provision is made for an annular web  46  which interacts with the container seal  9  in a sealing fashion. On its underside, the cover part  45  has a recess which forms the cover interior  47 . This loosely holds the head  29  of the plug  28 . 
     An evacuation apparatus  48  is provided in the cover part  45 , which evacuation apparatus  48  is adjacent to the cover interior  47  and is in the form of an evacuating valve  49  with a fitted protective cap  50 . 
     A corresponding evacuation apparatus  51  with an evacuation valve  52  and a protective cap  53  is installed in the outer base  6  of the insulation container  2 . As a result of this, it is possible for the insulation chamber  54 , which is formed in the insulation container  2  and completely filled with a vacuum-supporting material  55 , such as pyrogenic silicic acid for example. This effects a stiffening of the structure when the insulation chamber is evacuated. A getter  56  is installed in the base area of the insulation container  2  in order to bind residual gases in the insulation chamber  54 . 
     Provision is also made in the coolant chamber  21  for a metal wool filling  57  in addition to the coolant filling; as a result of this, thermal conduction within the coolant chamber is markedly improved and this assists the cold-loading and the liquid/solid phase transition of the coolant. 
     Optionally employed surrounding packaging  58  for the transport container  1  is shown in a vertical and a horizontal section in  FIGS. 2 and 3 , respectively. This surrounding packaging  58  comprises an outer container  59  with an outer cover  60 , which, by means of a peripheral sealing web  61 , meshes into a corresponding sealing groove  62  in the upper edge of the outer container  59 . The outer container  59  and the outer cover  60  are made from insulating material and have a quadratic outer cross section and a circular inner cross section. 
     The outer container  59  is produced as hollow body with an outer wall  63  and an inner wall  64 , with connection webs  65  extending between them. Together with the outer cover  60 , the inner wall  64  surrounds a cylindrical reception chamber  66  which is matched to the transport container  1 . 
     The cavity formed between the outer wall  63  and the inner wall  64  is also filled with a coolant  67 , which undergoes a solid/liquid phase transition in a comparatively high temperature range between C and −15° C. It can be water or saline. The surrounding packaging  58  and, in particular, the coolant  67 , which is frozen before use, form a barrier against the influx of heat into the surrounded transport container  1 . 
       FIGS. 4 to 13  illustrate the individual components which form the transport container  1  and how the latter is expediently assembled. 
     In accordance with  FIG. 4 , the cooling container  16  is provided with the metal wool filling  57 , the latter expediently being a tangled-up metal thread of copper, for example. This metal wool filling  57  is arranged in a substantially annular fashion in the cooling container  16 , as is made clear in  FIG. 6 , with a thin metal wool layer or at least one thread section remaining centrally above the base  5  of the cooling container  16 . 
     In accordance with  FIG. 5 , the inner wall  3 , with the female thread  13  and the constriction  12 , is pushed into the insulation ring  15 ; in fact, it is pushed in until it is in the position shown in  FIG. 6 , upon which the inner wall  3  is inserted into the cooling container  16 , as shown in  FIG. 6 , until the position shown in  FIG. 7  is reached. In this position, the bases of the inner wall  3  and of the cooling container  16  are supported on each other by a weld spot  22  and the cooling container  16  is fixedly connected at its upper end to the inner wall  3  by forming the welding bead  23 . 
     The cooling container  16  has on its upper side a thread opening  69 , through which, in accordance with  FIG. 8 , liquid coolant is poured into the former from a vessel  68 , until the cooling container  16  is substantially completely filled. This coolant is an organic substance with a solid/liquid phase transition temperature in the temperature range between −15° and −100° C., and preferably between −30° and −85° C., and has a heat of fusion of at least 50 J/ml. Such coolants can be, for example, octane 1-hexanol, 2-hexanone, hexanal, pyridine, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene or chlorobenzene. 
     After the filling, the thread opening  69  of the cooling container  16  is permanently hermetically sealed by virtue of the fact that, in accordance with  FIG. 8   a , a set screw  70  is firstly screwed in; the remainder of the opening remaining is then weld shut and subsequently the solder material  71  which is protruding is removed so as to be flush. 
     Now, in accordance with  FIG. 9 , the arrangement comprising the cooling container  16 , the inner wall  3 , and the insulating ring  15  is inserted into the outer wall  4  until it reaches the position in accordance with  FIG. 10 . In this position, the inner wall  3  and the outer wall  4  are connected in a vacuum-tight fashion to the insulating ring  15  by means of adhesive layers  72  and  73 , with the elastic mounting of the arrangement comprising cooling container  16  and inner wall  3  with respect to the outer wall  4  being achieved at the same time. 
     Subsequently, in accordance with  FIG. 11 , the insulation chamber  54  of the insulation container  2  formed within the outer wall  4  is filled with the vacuum-supporting material  55 , and the outer base  6  with the getter  56  is pushed onto the lower end of the outer wall  4  and connected in a vacuum-tight fashion to the outer wall  4  by means of an adhesive  74 , so that the arrangement shown in  FIG. 12  is obtained into which the container seal  9  is subsequently inserted at the upper end, and the evacuation valve  52  with the protective cap  53  is screwed in at the lower end in a vacuum-tight fashion, upon which the insulation container  2  is evacuated. In accordance with  FIG. 13 , the evacuation valve  49  is also screwed into the cover part  45  in a vacuum-tight fashion. 
     Finally, the plug  28  is completed in accordance with  FIG. 14  by installing the data logger  41 , the battery  42  and the temperature sensor  44  in it, and by attaching the O-rings  35  and the pad  38 . 
     The cold-loading of the transport container  1 , that is to say the phase transition of the coolant in the cooling container  16  from the liquid phase into the solid phase, can be effected in different ways and with the aid of differing devices which are explained in  FIGS. 15 to 19 . 
       FIG. 15  shows direct cold-loading with, for example, liquid nitrogen  75 , for the purposes of which a filling-funnel  76  is screwed into the female thread  13  of the open transport container  1  (without cover part  45  and plug  28 ) and provided with an open cover  77  during cold-loading. The filling-funnel  76  and cover  77  are produced from an insulating material. The advantage of this direct cold-loading is that the entire lower half of the inner wall  3 , including the inner peripheral wall  20  and the chamber floor  11 , is contacted by liquid nitrogen  75 , and hence active in transferring the cold, which is in the interests of a short loading time. However, extra care has to be taken that no (liquid) nitrogen remains in the sample chamber  24  and the neck opening  25  after the cold-loading has been completed. 
     In accordance with  FIG. 16 , provision is made for indirect cold-loading by means of liquid nitrogen (or else dry ice, or a dry ice/liquid mixture, such as isopropanol). A bowl-shaped cold transfer device  78  with a base plate  79 , from which a central long cooling finger  80  as well as an inner peripheral wall  81  and an outer peripheral wall  82  extend upward, is used for this purpose. An annular chamber  83  for the liquid nitrogen  84  is formed between the two peripheral walls  81  and  82 . The cold transfer device  78  is provided with an outer insulation  85  which surrounds the base plate  79  and the outer peripheral wall  82 . The base plate  79 , the peripheral walls  81  and  82 , and the cooling finger  80  are preferably produced in one piece from a material with a high thermal conductivity, such as copper. 
     For the purposes of cold-loading, the inner wall  3  of the transport container  1  is plugged onto the cooling finger  80  while the cover-free transport container  1  is an inverted position, the cooling finger being slightly longer than the wall, with the weight of the container ensuring good contact between the upper end face of the cooling finger  80  and the chamber floor  11 . In this case, the diameter of the inner peripheral wall  81  is dimensioned such that, as illustrated, it holds the lower end of the transport container  1  which is in the loading position. 
     In the case of loading in accordance with  FIG. 16 , the cold or heat is transported through the base plate  79  and the cooling finger  80  and, substantially, through the chamber floor  11 . The heat exchange with the coolant in the cooling container  16  is mainly carried out by the metal wool filling, which also extends between the chamber base  11  and the inner base  5 , and which substantially shortens the cold-loading time in view of the poor thermal conductivity properties of organic coolants. This is also assisted by the fact that the heat is transmitted through the chamber base  11  at the highest point of the coolant, which sinks downward during cooling, and thus improves the overall freezing of the coolant. 
     In accordance with  FIG. 17 , provision is made for indirect cold-loading, which corresponds to the cold-loading in accordance with  FIG. 16 , by means of an active cooler  86  as a source of cold, e.g. a Stirling cooler. From this, a correspondingly long metallic cooling finger  87 , made from a material with a high thermal conductivity such as copper, again extends upward. 
     In accordance with  FIGS. 18 and 19 , provision is again made for indirect cold-loading; however, in this case, it is made for passive cooling which is effected by insertion into a freezer room. For this purpose, a cold transfer device  89  is provided which in turn has an upwardly extending cooling finger  90  which is connected at its lower end to lamellae  91  which are arranged in a star shape, as shown in  FIG. 19 . In this case too, the cooling finger  90  and the lamellae  91  are composed of a metal with a high thermal conductivity, such as copper. 
       FIG. 20  illustrates the assembly of the transport container  1  ready to be sent, in which the plug  28  has been inserted and screwed-in in accordance with arrow  1 , until its neck seal  33  is pressed against the valve seat  34  in a sealing fashion. In accordance with arrow  2 , the cover part  45  is then put on, whereupon, in accordance with arrow  3 , the cover interior  47  is evacuated by means of the evacuation valve  49 . The external excess pressure effected in this fashion ensures that the cover part  45  pushes on the insulation container  2  in the axial direction while it is securely sealed by means of the container seal  9 . At the same time, heat transfer by convection in the annular gap  32  is suppressed. 
     The cooling container  16  with the frozen coolant is then screened from the influx of heat by the superinsulation formed by the evacuated insulation container  2 , and by the plug  28  with its insulation shaft  30 , and by the evacuated annular gap  32  around the insulation shaft  30 , so that the frozen state or the cold-loading is maintained as far as possible, even in the surrounding temperature while being sent to the site of operation (hospital). 
       FIG. 21  illustrates the use at the site of operation. The protective cap  50  is removed, the cover interior  47  is ventilated by actuating the evacuation valve  49 , the cover part  45  is removed and the plug  28  is unscrewed and removed in accordance with the steps in indicated by arrows  1  to  4 ; after this, the frozen samples  26  in the sample containers  27  are inserted into the sample chamber  24 . Subsequently, the transport container  1  is sealed again as soon as possible in reverse order, specifically by screwing in the plug  28 , putting on the cover part  45 , evacuating the cover interior  47  and putting on the protective cap  50 . This results in the state illustrated in  FIG. 1 . Now the samples  26 , which are protected from heating up by the above-described insulating effect of the transport container  1  and in particular the cold capacity of the frozen coolant in the cooling container  16 , can be sent to their destination. If necessary, this is also possible without using the surrounding packaging  58  in accordance with  FIGS. 2 and 3 . The surrounding packaging  59  is used in particular in the case of long storage periods and/or transport periods, and in the case of relatively high surrounding temperatures. 
     At the destination, the samples  26  are then removed from the transport container  1 , analyzed and possibly permanently stored in a freezer room. The data logger  41  is used to check that the envisaged storage temperature in the sample chamber  24  was maintained and the samples  26  were correspondingly not damaged. 
     Provision is made for the transport container  1  to be reused; to do this only requires renewed cold-loading and the previously described assembly, and sending it to the site of operation. Moreover, it is suggested to check and renew the evacuation of the insulation container  2  after empirically defined time intervals. 
     In summary, the transport container according to the invention can be described as follows: the transport container  1  comprises superinsulation in the form of an evacuated insulation container  2  with a vacuum-supporting material  55 . A cooling container  16  is integrated therein, which contains a thermally-conducting metal wool filling  57  and which is filled with an organic coolant which undergoes a solid/liquid phase transition in the temperature range between −30° and −85° C. and which has a heat of fusion of at least 50 J/ml. Provision is made for a thin, cylindrical sample chamber  24  for holding deep frozen tissue samples  26 , which chamber is surrounded by the cooling container  16  and integrally merges into a long neck opening  25 , which in turn is substantially filled by the insulating shaft  30  of a plug  28 , which can be screwed in, and sealed with respect to the sample chamber  24 . The annular gap  32  which then remains can be evacuated by means of an evacuation apparatus  48 . The plug  28  is provided with a pad  38 , extending into the sample chamber  24 , and a data logger  41  for recording the temperature in the sample chamber  24 . After the coolant has been frozen, the transport container  1  makes transport times and intermediate storage of up to 14 days possible without any risk to the held tissue samples  26 .