The invention relates to a method for manipulating samples, in particular tissue samples, wherein by means of needles holes are punched from sample carriers and samples are punched-out from preparations, in particular prepared tissue specimens, and said samples are inserted into holes punched-out of the sample carrier, wherein the position of the surface of the sample carriers or preparations is detected prior to the punching process.
In addition, the invention relates to a device for manipulating samples, in particular tissue samples comprising at least one needle for punching holes into sample carriers and at least one further needle for punching samples out of preparations, in particular prepared tissue specimens, wherein a device for detecting the position of the surface of the sample carriers is provided.
The term “preparations” particularly includes tissue specimens from humans or animals, but also other biological materials. With the methods of the present invention and the device of the present invention for instance embedded cell pellets or embedded bacteria suspensions, but equally plant specimens can be processed and so called sample arrays produced from them.
Biological tissues are removed frequently from human or animal organs for medical as well as scientific purposes and, following a series of preparation- and processing steps, used in various assays, for instance to identify diseases, changes in tissue or for the assessment of the progression of therapies. Thereby the removed tissue is generally embedded in paraffin, synthetic material or another, comparable material and one or more specific samples punched-out from said embedded tissue specimens. For this purpose cylindrical tissue samples are punched-out with needles. Said punched-out tissue samples are then inserted into punched-out holes of equivalent size on a sample carrier also punched-out with the help of needles. The sample also carrier generally consist of paraffin, synthetic material or a similar material. Furthermore, materials that exhibit gel-like consistency and harden at a low temperature are established for embedding the preparations and for inserting the samples. Such thermoplastic substances are particularly suited for the manipulation of frozen samples. Needles are used to punch holes in the sample carrier, whose outer diameter essentially corresponds to the inner diameter of those needles that are used to punch tissue samples from tissue specimens. Consequently, the punched-out tissue sample fits exactly into the punched-out hole in the tissue carrier. In this way, the so-called tissue arrays or micro arrays containing a large number of adjacently arranged tissue samples are produced. From the thus produced tissue sample arrangements, sections are prepared, usually with a microtome that can be applied to histological or pathological analyses. In doing so several hundred tissue samples can be arranged on sample carriers possessing an area of for instance 3 to 4 cm. The number of individual samples resulting from the preparation of the sections and requiring evaluation is correspondingly high. Because of the enormous number of tissue samples, the manipulation of the tissue samples should be carried out as fast as possible and be automated. For that purpose, devices for manipulating tissue samples have been developed, with the help of which, such tissue arrays can be produced as fast as possible and with as high a degree of accuracy as possible.
U.S. Pat. No. 6,103,518 A, for example, describes a device of the present kind for manipulating tissue samples, where holes are punched-out from sample carriers and tissue specimens by means of a needle and tissue samples are punched-out with a further needle and said tissue samples inserted into the punched-out holes in the sample carriers. Because the sample carrier and the tissue specimens are usually of different height, the needle is connected with equipment for detecting the position of the surface of the sample carrier or the tissue specimens respectively. Thereby the detection of the surface occurs with the help of the ejector positioned within the needle, which when the needle is displaced is extended in the direction of the sample carrier or the tissue specimens and consequently first touches the surface of the sample carrier or the tissue specimens. The ejector is spring supported and is displaced relative to the needle holder after touching the surface of the sample carrier or the tissue specimens. This displacement is detected electronically or optically. A predefined punching depth can always be achieved by detecting the surface of the sample carrier or tissue specimens, in order to obtain equally large holes and tissue samples as a consequence. Thereby it is disadvantageous that the spring support of the ejector as well as the electronics and optics for detecting the displacement of the ejector relative to the needle or the needle holder, are complex and consequently expensive but also prone to mistakes. Furthermore, optical detection methods are particularly problematic, since contaminations, as they might be found in such manipulations with tissue samples, could lead to erroneous measurements.
The aim of the present invention is to create a method for the manipulation of samples, in particular tissue samples, of the kind described above, which is accomplished as simply and as fast as possible and with which samples in particular tissue samples can be produced exhibiting the highest possible quality and specificity.
A further goal of the present invention is therefore to build a device for manipulating samples, in particular tissue samples, of the kind described, which is as simple and economical as possible and as maintenance-free as possible. The device should be able to array as many samples as possible in sample carriers provided for it, without destroying an excessive number of these in the process. The device should carry out the manipulation of samples, in particular tissue samples, as automatically as possible. Disadvantages of the state of the art should be avoided or at least reduced.
According to the invention the first task is solved through detecting the surface of the sample carrier or preparation by suction lines opening into the needles, whereby the negative pressure generated by the needles approaching the surface of the sample carrier or preparation, is detected within the suction line, and that the needle is inserted into the sample carrier or preparation, to a predefined insertion depth, based on the detected position. The detection of the height or position of the sample carrier or preparation, by means of negative pressure represents at the same time a simple but also robust and accurate procedure. In practice the needle for punching holes from sample carriers or punching-out the preparations, in particular tissue specimens, is moved with a specific speed, continuously or step by step, in the direction of the sample carrier or preparation. When the needle is situated near the surface of the tissue sample or preparation, a negative pressure is generated within the suction line, since the amount of air that can be sucked by the needle through the suction line, is no longer sufficient. Said negative pressure can be detected with the help of certain measuring devices and the movement of the needle towards the sample carrier or preparation, stopped when a certain value is exceeded. The so achieved position of the needle in relation to the sample carrier or preparation corresponds to the height of the sample carrier or preparation with a relatively high degree of accuracy. Consequently, the surface of any sample carrier or preparation can essentially be determined accurately without contact and from said position the needle can always be inserted with a predefined punching depth into the sample carrier or preparation, thus resulting in a consistent quality of the punched-out holes, as well as of the punched-out samples, in particular tissue samples. Additionally, it can be prevented, that samples are either arranged too deep within the holes of the sample carrier, or protrude from the holes of the sample carrier, leading to a higher wastage during the production of the sections from the micro array or the tissue array respectively, because the resulting thickness of the array, from which the sections can be produced, is smaller.
Advantageously, the detected position values are stored in conjunction with an identifier for the sample carrier or preparation. Thus, by choosing a specific sample carrier or preparation with their identifier, the associated position value can always be read from the storage device and applied to the control system so that the needles can always be inserted into the sample carrier or preparation exactly in the predefined punching depth from the surface of the sample carrier or preparation.
It is intended for the punching depth to be variable in order to adapt the method to different prototypes, in particular tissue types or examination procedures.
During the method for manipulating samples, in particular tissue samples, the needle can be mechanically freed from the material residing therein after the punching process, by means of an ejector arranged within the needle and afterwards the needle cleared with compressed air. In this way, a secure removal of the punched-out sample carrier or the punched-out sample can be achieved. During a purely mechanical removal, by means of an ejector, material frequently gets caught at the edge of the needle. By cleaning the needle with compressed air that is preferably introduced into the needle through the suction line, such caught material may be removed with exceedingly high probability.
The needle is submerged in a cleaning fluid, after at least one punching process, and afterwards cleared with compressed air in order to remove contaminations from the needle, in particular by paraffin or equivalent of the sample carrier or of constituents of the preparations. The cleaning fluid, which in the case of the paraffin of the sample carrier solubilizes paraffin, consequently effects a loosening of the paraffin residues and thus an effective cleaning. With the ensuing blow of compressed air that is preferably also applied through the suction line, a remaining of the cleaning fluid on the needle, that may entail damage of the samples, can be prevented.
According to a further feature of the invention it is tested by means of negative pressures if the needle is clear in order to detect possible contaminations. This test can be carried out without additional devices with the device for detecting the position of the surface of the sample carrier or preparation.
Advantageously, the detection of the position, the punching processes, the ejection procedures and if need be the cleaning and permeability test of the needle are controlled by a timer. Thus, a semi automated or fully automated manipulation of the samples, in particular tissue samples, can be achieved.
In order to subsequently achieve an unambiguous assignment of the individual samples arranged in the sample carrier when analysing the sections produced from said sample arrays, it is intended to arrange the holes for the samples in the sample carrier in a pattern, which is generated by arranging the holes in terms of a binary code. By using such a layout an unambiguous assignment of the samples within the arrays can be achieved. In this way the delivery of incorrectly assigned measurements from the section of the sample due to upturning the slide or turning the slide can be prevented. Naturally the samples can be arranged in various different patterns, which unambiguously determine the direction of the array.
Thereby, the manipulation of the samples occurs preferably temperature-controlled. Thus, for example frozen preparations can be processed under low temperatures as well and the punched-out frozen samples manipulated.
According to the invention the second task is solved by an above mentioned device for manipulating samples, in particular tissue samples, in which the device for detecting the surface of the sample carriers or preparations is formed by suction lines opening into the needles, wherein said suction lines are connected with a device for generating a negative pressure and furthermore with a device for detecting a negative pressure so that the approach of the needle towards the surface of the sample carriers or preparations can be detected by the resulting negative pressure, and that a drive unit for displacing the needles relative to the sample carrier or preparation, from the detected position of the surface to a predefined punching depth, is provided. Such a device, constituted by a suction line, is relatively inexpensive and easy to produce, and furthermore robust, and consequently not prone to errors. The present device for manipulation is essentially capable to detect the position of the surface of the sample carrier and preparation without contact and, as a consequence, can always punch-out holes or samples with a defined punching depth. As a consequence a high quality and specificity of the micro arrays, in particular tissue arrays, result and thus a high quality of the resulting measurements of samples, in particular tissue samples.
Advantageously, the device for generating a negative pressure is constituted by a vacuum pump. Said vacuum pump is connected with the suction lines and preferably also comprises at the same time the device for detecting the negative pressure.
According to a further feature of the invention, a storage device is provided for the detected position values of the sample carriers or preparations in conjunction with an identifier for said sample carriers or preparations. Consequently, in particular in devices for extremely high numbers of sample carriers or preparations, an unambiguous assignment of the position values to all sample carriers or preparations can be carried out.
The opening of the suction line into the needle can simply be realized by means of a cross-hole, into which the suction line opens.
The usually notably small and thin needles are arranged in a needle retainer, for easier manipulation, which possess a drilled hole that corresponds with the opening of the needle. Thereby the suction line can be attached at the needle retainer und the suction line joined via the needle retainer with the relatively small cross-hole in the needle.
A unit for changing the punching depth can be provided in order to adjust the device to various preparations, in particular tissues or to various assay procedures respectively.
An ejector that is preferably operated pneumatically is arranged within the needle, in order to remove the punched-out materials of both the sample carrier and the sample.
According to a further feature of the invention, a waste container is provided to receive the punched-out materials of the sample carriers. The specimens ejected by the pneumatically operated ejector, are thrown into it.
In order to clean the needles, a cleaning reservoir can be provided, into which the needles can be submerged. By submerging them into the cleaning reservoir, between several punching processes the hole-punching needles as well as the sample punching needles can consequently be cleared from residues of the sample carriers as well as of the samples.
For an optimal manipulation of the samples, in particular tissue samples, it is intended that the waste container and if need be the cleaning reservoir are arranged between the sample carriers and the preparations or between a support carrying the sample carrier and a support carrying the preparations respectively. Thereby manipulation can be carried out, within the shortest possible route, and consequently in the briefest time.
The supports for the sample carriers and for the preparations preferably have a circular shape and are arranged next to each other, in that way the sample carrier and the preparation, that are processed at a given time, can be arranged as close to each other as possible so that the punched-out sample, in particular tissue sample, can be inserted into the sample carrier by the shortest and fastest route. In order to change the sample carrier and the preparation, the supports are appropriately displaced relative to each other.
Preferably, at least one hole-punching needle and at least one sample punching needle are mounted on a shared pivoting head, wherein the axis of the hole-punching needle and the sample punching needle are intersecting each another at the pivot point of the pivoting head. Consequently, a change between hole-punching needle and sample punching needle can be achieved by simple swinging of the pivoting head. Furthermore, solely one drive unit for the pivoting head must be provided rather then multiple drive units for each needle.
The pivoting head is thereby preferably operated through a pneumatic pivoting drive.
In addition, a drive unit is provided for displacing the pivoting head relative to the sample carriers or preparations. This can either be arranged in the pivoting head, in the support, or in the support for the sample carriers or preparations, so that a displacement of the pivoting head or the needles relative to the sample carriers or preparations is achievable. This drive unit is preferably constructed pneumatically as well.
Advantageously, a control system is provided, for controlling the detection of the positions, the punching processes, the ejection procedures and if need be the cleaning procedures, which can for instance be represented by a computer. The overall control of the manipulation device is carried out by means of said computer, so that the procedure can be carried out automatically of at least semi-automatically after accordant specifications of the punching depth and the position on the preparations, at which the samples should be punched-out.
Advantageously, a device for controlling the temperature is provided, to facilitate the manipulation of frozen samples in particular. This ensures that the manipulation is carried out at predetermined temperatures. For that purpose the entire device is advantageously arranged under an appropriate cover sheet.
The present invention is further illustrated by means of the drawings, which demonstrate the principal and embodiments of the invention.
Therein show:
Said drilled hole 28 in the needle retainer 22 is shown in the sectional representation of the needle retainer 22 according to
Number | Date | Country | Kind |
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A 1648/200 | Oct 2002 | AT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AT03/00325 | 10/30/2003 | WO | 4/29/2005 |