WO2008128360A1 - Usable space having external microbe suppression - Google Patents

Abstract

In the usable space of a device for the storage/preparation of biological samples, a UV sterilization device having a UV lamp (21) is provided. Said UV lamp is arranged in a dedicated partial space (40) in which the usable microbes are not present, so that the UV light cannot reach the usable microbes. This permits a substantial reduction of air-borne microbes in the circulating air, even during the intended operation of the device. In addition, at least part of the surfaces of the usable space is made of a copper-nickel alloy, which prevents the growth of harmful external microbes on the surface.

Description

 Workspace with Fremdkeimunterdrückrung

The invention relates to a device with a usable space for storing and / or preparing biological samples and / or goods, in particular an air-conditioning cabinet, according to the preamble of the independent. Claims.

A typical climatic cabinet has a utility room for receiving biological samples and may be used as an incubator or refrigerator, e.g. in biological laboratories. Br must generally be set to a defined starting state (zero state, "reset") before the input of samples, in particular the Mutzraum, a possible built-in mechanical structures, be free from germs of any kind.

During the production of this initial condition, hostile conditions must prevail for microorganisms and this must be free from biological samples of any kind, as well as their. Currencies.

In general, immediately after the germ-free initial state has been established, the germs intended for storage, cultivation and propagation, hereinafter referred to as useful germs, are transported through special loading hatches or simply manually through the front door into the working space , The media required for storage, cultivation or multiplication of the useful germs are either automatically added to the mutzraum together with the useful germs or later. The biological task), exact climatic conditions, especially in zug on temperature, humidity and gas atmosphere, must be given.

In general, the biological task requires that only the useful germs thrive or conserve in the working area. However, as a result of accidental events and due to operational operations / manipulations, other germs, in particular harmful germs, in the following referred to as foreign germs, can be introduced during their storage, cultivation and / or propagation, which may have a negative or even destructive effect on the Kutzkaime. The present invention therefore has as its object the obstruction of the propagation of introduced foreign germs and, in the most favorable case, even killing these germs without impairing the useful germs.

Essentially, the foreign germs pass either airborne from the gas phase or object-worn, for example, over the user's hands, sample containers or sample manipulators into the mutzraum. From the intake air, for example, foreign germs are transported airborne through the leaks of the useful space container, in particular at the edges of access openings, and through the access openings themselves, especially during manual or automatic sample changes during the breeding or storage phase.

The invention is based on the idea that foreign nuclei must be located either on surfaces or in the air space within the useful space due to random events.

As long as these foreign germs are airborne, they can not multiply. Only when foreign matter is able to settle on solid, liquid surfaces or in liquids itself is a basic prerequisite for their growth multiplied.

The invention is based, in a first aspect of the Gadanke, on killing the airborne foreign germs directly or indirectly. In a second case She is based on this; to kill or at least prevent growth on solid, moist or in liquid sites foreign germs, as far as the Nutzkeirae are not destroyed or disturbed.

According to the first aspect of the invention, the device is designed so as to allow sterilization of the air in the working space after the samples have been taken, i. during the presence of the samples in the work space. In other words, a sterilization of the air should not affect the simultaneous development of the NutzkeiTne.

For this purpose, the UV radiation is preferably shielded from the useful germs located in the useful space (20).

Preferably, the air in the working space 20 is set in circulation and passed completely or partially through a subspace (40), which is penetrated by germicidal ultraviolet radiation.

A second aspect of the invention relates to the killing or obstruction of foreign objects in places that are not necessarily reached by the UV radiation, either because they are in design-related niches and columns, or if it is because the foreign nuclei in immediate nearer to be protected useful germs.

For this purpose, at least a part of the surfaces of the useful space is designed for the emission of copper ions. Preferably, this part of the surfaces is made of an alloy comprising pluck and nails.

Further preferred embodiments of the invention will become apparent from the dependent claims and from the following description with reference to FIG. 1, which shows a section through a climatic chamber.

The disinfecting and germicidal effect of UV radiation and their use, for example in room air conditioners has long been known. The heat loss generated by the UV lamps is for the usual technical applications without or of lesser importance but not for the inventive air conditioning cabinets, the temperature and humidity household would be disturbed sensitive.

In the device described here, this heat loss is now dissipated by a separate fluid.

Fig. 1 shows a schematic, vertical section through a climatic cabinet 48. He has a Nutsraum 20, in which fittings 25 are provided. This may be, for example, one or more storage shafts for receiving several laboratory samples on top of each other. Further, in the work space 20, e.g. a transport device for manipulating the stored in the internals 25 laboratory samples may be provided. A user door consisting of outside door 27 and inside door 26 allows manual access to the utility room. Additionally or alternatively, an automated door may be provided for access by robot. An example of a corresponding device is e.g. in US Pat. No. 6,478,524.

In Klimasσhrank 48 a subspace 40 is further arranged, through which circulates air with a fan 42 from the rest of Mutsraum. In the present embodiment, the subspace 40 is arranged vertically, a lower air inlet opening 44 and an upper air outlet opening in the area of the fan 42 suit.

For a climate chamber important features that are not the subject of this invention, such as measuring and control elements for temperature and humidity in the Nutzraum are omitted. However, it is well understood that these control variables are important for a climatic chamber. The device described here improves BSW. simplifies the regulation of these quantities.

The climatic chamber is using funds; which are directed to the fact that all in the Nutsraum 20 foreign germs that are still airborne, are intercepted and killed. The curly arrows 22 are the Indicate air movement within the usable space 20 including the subspace 40.

The internal air delivery is, as mentioned, forced by a fan 42, which sits at one end of the subspace 40. The air inlet opening 44 at the other end of the subspace 40 and the air outlet opening on the fan 42 are barred or provided with labyrinths, so that no direct light from the lumen of the subspace can get into the rest of the lumen of the work space.

Inside the subspace 40 is a tube 8 made of quartz glass (or another, for UV light at least partially permeable chamber), the inner lumen has no fluid communication with the lumens 20 and 40 and is separated from these gas-tight. Through the pipe 8, an outside air flow 41 is forced by means of fan 39 between the pre-air opening 38 and the exhaust opening 29. This air flow 41 serves to cool a suitable UV emitter, which sits concentrically in the quartz tube 8.

By virtue of this arrangement, the air streams 22 and 41 are completely decoupled and thus the energy exchange between the lumens of 8 and 40 largely, especially because of the very weak thermal conductivity of the quartz glass of 8. The electrical heat loss of the UV lamp 21 can almost completely with the air flow 41 are discharged, except for a rest, which is caught by the temperature control of the climatic chamber.

In this way, the use of UV lamps 21 is also relatively higher power than previously possible.

The glasses of both the tube 8 and the UV emitter 21 have the same spectral transmittance for the characteristic wavelengths of a suitable UV emitter, in particular 254 nm, but not for the ozonogenic UV radiation, so that the air in the partial room 40 is acted upon by germicidal but not ozonogenic radiation.

The partial space wall 47 preferably bears transverse webs 45 on the side facing the UV emitter 21, which effect a swirling of the flow 22, such that airborne germs on the inner UV emitter surfaces of the partial space 40 are liable to adhere with great probability.

At least a part or surfaces of the subspace 40 are preferably coated with titanium dioxide, in particular titanium oxide particles 46. It is known that titanium dioxide particles have a strong catalytic effect, which kills bacteria of diverse species under the irradiation of UV light, in particular in conjunction with the high humidity in the flowing air 22.

The probability of destroying a free air-borne foreign germ with one or more UV light quanta (while at the same time protecting the stored material) is smaller by orders of magnitude, that is negligible, than that of a foreign germ accommodated on a wall.

The foreign nucleation strategy described so far thus provides i.a. to fix the initially airborne introduced Premdkeime as quickly as possible to surfaces that are acted upon by UV light.

However, part of the introduced premi-germs will also be accommodated outside the UV-irradiated areas, especially near the beneficial germs, which may not be exposed to UV radiation by intention. Here another strategy must be pursued.

Another necessary condition for the growth of foreign germs is their embedding in water. However, it is known that copper ions (Cu ions) on microorganisms such as viruses, bacteria, fungi, etc. have a killing or at least growth-inhibiting effect. vice On the other hand, microorganisms that are resistant to Cu ions are virtually unknown.

The first description of this so-called oligodynamic effect is found. In the original work of K. W. Nägeli in 1893: On oligodynamic phenomena in living cells. New Denkschr. Generally. Switzerland. Gesellsch. Ges. Näturwaiss. Bd XXXII Dept. 1. Even today, the exact causes of the antimicrobial mechanism of action are still unclear.

A probable explanation is the disruption or blockage of the redox systems in the cytochrome complexes of the mitochondrial respiratory chain of the microorganisms by Cu ions in the cell fluid (see E. Strasburger, Textbook of botany, 35th edition, 2002, 3 321). The Cu ions directly attack the mentioned ionic redox couple by electron scavenging. The energy-supplying electron transport in the respiratory chain as a central metabolic function comes to a standstill.

It is important that the beer-forming neutral Cu atoms in the cell water are re-ionized by solvation. The "spent" Cu ions are thus regenerated and are thus constantly available for the blockade of the respiratory chain.

With regard to the desired obstruction or killing of foreign germs which are akkotodiert on the inner surfaces of Nutzräuinen, there is the situation that, as soon as in the work space a point with condensed water is present, there is a condition for germination, if the condensed water is connected to a Cu ion supplying surface. In this situation both conditions are logically strictly linked: germ growth is excluded. In addition, any germs already introduced, for example in a nutrient medium, can be destroyed.

Cu-ion supplying surfaces in the utility rooms of climatic cabinets are known per se for a long time. However, this technique has not prevailed because copper surfaces, are unstable to the changing atmospheric conditions within the mining areas and are passivated after more or less long periods of time _; in the sense that they can donate little or no more Cu ions in an aqueous medium. For example, a closed copper sulfide surface is not at all, a closed copper (II) oxide surface is almost unable to form Cu ions.

Therefore, it is now proposed to provide at least a portion of the surfaces in the work space 20, preferably all objects of the work space 20 including its inner walls 24 and 47, its internals 25 and 45 and all other objects in the common with the Nutzkeimen gas space with surfaces which Cu -Ions in a Wäsariges medium permanently can deliver. In particular, those surfaces which share the gas space together with the useful germs should be able to release copper ions.

In particular, the storage shafts for receiving the laboratory samples with copper-ion emitting surfaces may be configured or consist at least partially of a copper-nickel alloy.

The surfaces mentioned can now be solid or only superficially made of Cu-ion supplying materials. The materials must be chosen so that on the one hand the surfaces are stable, on the other hand they are able to release Cu ions in sufficient quantities. So a compromise between Cu-ion activity and surface passivity has to be found.

Preferably, the said objects or the substrates of the surfaces are made of an alloy comprising copper and nickel, in particular a copper-nickel alloy, with a nickel content of between 10% and 30%. Accordingly, the copper content should be at least 70, but not more than 90%. An object made of this material automatically overlaps normality. aphäre or after chemical treatment with a nickel hydroxide layer, which exerts a passivating effect on the surface on the one hand and on the other hand still enough Cu ions from deeper layers delivers. The concentration interval of 10% to 30% nickel gives the optimum in terms of the desired compromise mentioned above.

In a further embodiment, it is proposed according to the invention to provide the objects in the work space only with a Cu-ion-supplying and yet long-term stable surface. It is particularly advantageous to manufacture objects with large volumes, for example supports, base frames etc., for reasons of weight, of aluminum and then to treat the surface in such a way that it is capable of dispensing copper, in particular by means of a suitable coating.

For this purpose, the objects made of aluminum can first be treated by conventional anodic oxidation processes and subsequently the conventionally produced oxide layers can be penetrated by means of copper salt solution using alternating current with copper. In general, objects made of aluminum or aluminum alloys in the work space, such as e.g. Parts of the internals 25, be provided on its surface with a copper-containing layer.

The invention also relates to the method described above for producing these objects.

Claims

claims 1. A device with Nutsraum (20) for the controlled storage and / or preparation of biological samples and / or goods, in particular climatic chamber, characterized in that the useful space, after the inclusion of samples and during their presence in the work space by the direct or indirect effect of in a partial area. (40) mounted UV emitter is sterilizable. 2. Device according to claim 1, wherein the UV radiator is a Hg low-pressure lamp with a Hg-steam- or Hg-Amalgamdaτrϊpf filling, which emits germicidal and non-ozone radiation. 3. Device according to one of the preceding claims, wherein the Nutzkeime in the work space (20) are shielded, such that light emitted by the UV lamp (21) light can not reach the Nutzkeimen. 4. Device according to claim 3, wherein at least one fan (42) is provided to circulate air between the subspace (40) and the non-UV-irradiated portion of the work space (20) su. 5. Device according to claim 4, wherein on a wall of the subspace (40) means for swirling in the subspace (40) running air flow are arranged, and in particular that these means are configured as transverse webs (45). 6. Device according to one of claims 4 or 5, wherein at least a part of the wall of the subspace (40) with titanium oxide (46) is coated. 7. Device according to one of the preceding claims, wherein the uv radiator (21) in a UV for UV Light is arranged at least partially permeable chamber (8), the interior of which is separated gas-tight from the useful space (20) and from the subspace (40), wherein the UV emitter with a located in the chamber (8) or through the chamber (8) flowing fluid is coolable. 8. Device according to claim 7 with at least one fan (39) for flushing the chamber (8) with cooling air, and in particular wherein the chamber (8) has a pre-air opening (38) and an exhaust air opening (29) for ambient air. 9. Device, in particular climatic chamber, in particular according to one of the preceding claims, with a usable space (20) for the controlled storage and / or preparation of biological samples and / or goods, characterized in that at least a part of the surfaces (24, 47) of the usable space ( 20) and / or the subspace (40) is designed for the release of copper ions. 10. A device according to claim 9, wherein the copper ion donating surfaces are made of an alloy comprising copper and nickel. 11. A device according to claim 10, wherein the alloy comprises between 10% and 30% nickel and / or between 70% and 90% copper and in particular that the alloy is a copper-nickel alloy. 12. Device according to one of claims 9 or 10, wherein a nickel hydroxide layer is disposed on the alloy. 13. Device according to one of claims 9 to 12, wherein at least a part of the surfaces is coated with a copper ion donating coating. 14. Device according to one of claims 9 to 13, wherein substantially all surfaces (24, 47) of the useful space (20) and / or the partial space (40) are designed for the release of copper ions. 15. Device according to one of claims 9 to 14, wherein in the work space (20) at least one storage shaft (25) for receiving a plurality of laboratory equipment is arranged, wherein at least a part of the surfaces of the bearing shaft (25) is designed for the discharge of copper ions and in particular that the storage structure at least partially consists of an alloy containing copper and nickel. 16. Device according to one of claims 9 to 15, wherein in the work space (20) at least one object made of aluminum or an aluminum alloy is arranged, whose surface is provided with a copper-containing layer. 17. Device according to claim 16, wherein the surface of the object is treated with oxide and is subsequently treated with copper sulphate. 18. Method for producing a Device with an object according to claim 16, wherein the surface is oxidized and then interspersed with copper salt solution using alternating current with copper.