GB2073413A - Apparatus for reading samples - Google Patents

Abstract

Apparatus for the opto-densitometric reading of samples, in particular electrophoretic samples, comprises disc-shaped support 11 which carries the samples disposed peripherally. Means 3, 5, 9, 10 are provided for angularly moving the support, and reading means 26, 28 are provided to read the samples on the support. The samples may have a foil supports 12 mounted as radial or peipheral strips. <IMAGE>

Description

SPECIFICATION Apparatus for reading samples The invention relates to apparatus for reading samples, and more particularly to apparatus for opto-densitometric reading of samples, especially electrophoretic samples, or other similar laboratory apparatus.

In the case of biological samples processed for example by electrophoresis or other means, multiple samples are generally obtained in the form of parallel strips spaced equally apart at a predetermined pitch on foil supports which can be adapted for reading in transparency or by reflection. It has been proposed to use apparatus in which a single foil support carries a limited number of strip samples simultaneously obtained, and the optical reading is carried out mainly individually and successively for the various samples, with a relative displacement between the reading head and the foil support after the reading of each sample. This previously proposed apparatus is relatively slow and bulky.

According to the invention, there is provided apparatus for the reading of samples, comprising a disc-shaped support carrying the samples, means for angularly moving said support, and reading means for reading the samples.

Further according to the invention, there is provided apparatus for the opto-densitometric reading of samples, comprising a rotatable support arranged to carry the samples in strip form, and a reading system operative to read the successive samples during rotation of the support relative to the reading system.

Each of the samples can extend stripwise with a chromatically variable sign in the direction of the strip length. In this case, each of several groups of side-by-side strip samples can be disposed with the strip samples positioned perpendicular to a substantially radial direction, adjacent groups of samples being disposed along a circular line on the support for their reading during the rotation of the support. The reading means can comprise a reading head capable of reading one strip sample at a time, means being provided to advance the head in a direction approximately corresponding to said substantially radial direction, the advancement being each time through a distance equal to the distance between the adjacent strip samples of any one group for each revolution of the support.

More particularly, each unit advancement of said head can be effected after each revolution of the support and during a short halt thereof.

Alternatively, the strip samples can be disposed in a layout which is substantially tangential to a spiral, and the head is then advanced with continuous motion sychronously with the discoidal support.

According to a further alternative, the reading means can comprise several reading heads disposed substantially aligned radially and spaced apart, to correspond to the strip samples of any one group, to allow simultaneous and selective reading of the samples.

According to a further embodiment, the strip samples can be disposed in a substantially radial position, and a reading head of linear extension and positioning corresponding to the samples is then arranged to simultaneously and selectively read all the zones of any one sample, and then of adjacent samples.

The support can be arranged to receive sample groups disposed side-by-side, each of the groups being carried by a foil support independently of the others.

The support can be arranged to receive a foil support in the form of a circular ring, which is common to all the sample groups.

Embodiments of the invention, will now be described by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a schematic longitudinai section through one embodiment of apparatus in accordance with the invention, the section being tal < en diametrically through a disc-shaped support; Figure 2 is a fragmentary plan view on line Il-Il of Fig. 1; Figure 3 is a plan view of the disc-shaped support with a modified layout of the foil supports for the samples; and Figures 4 and 5 are plan views similar to Fig. 2 showing further modifications.

As shown in the accompanying drawings, the reference numeral 1 indicates a base for supporting, by bearing means3, a vertical shaft 5 on which a disc-shaped support 7 is mounted. The shaft 5 is rotated by an electric motor 9, of synchronous, stepping or direct current type, via a worm-helical gear coupling 10, 11, using a control program as described hereinafter.

The support 7 comprises a plurality of seats 7A around its periphery. Each seat receives a foil supprt 1 2 of the type used for multiple strip samples in electro-phoresis and other methods. The foil supports 1 2 are arranged, in the embodiment of Figs. 1 and 2, so that the strip samples (parallel and equidistant from each other) are positioned perpendicular to an intermediate radial direction.

A threaded shaft 1 4 is mounted on the base 1 and is positioned within its axis horizontal and perpendicular to the axis of the shaft 5. The threaded shaft 1 4 can be rotated by means of a stepping motor 1 6 in accordance with a control program described hereinafter. A lead nut 18, forming part of a slide indicated overall by 20 and arranged to be guided in a direction radial to the support 7, is coupled to the threaded shaft 14. The slide 20 is bifurcated and comprises a pair of arms 227 24 which embrace the periphery of the disc 7 at a reading zone. A bundle of optical fibres 26 is combined with the upper arm 22 for optical connection to a photodetector indicated by 28, which in its turn is connected to circuits for processing the signals.A bundle of optical fibres 30 originating from a light source 32 correspondingiy reaches the lower arm 24 of the slide 20. This arrangement is provided for reading the transparency of the sample using a beam of optical radiation originating from the fibres 30 and which, by way of the sample, reaches the fibre bundle 26 to supply the photodetector 28 with the optical signal modulated by the sample.

In the apparatus as described, the foil supports 1 2 located on the support 7 each comprise a sample on a circumferential line common to all the foil supports, and thus.the number of circumferential lines of samples is equal to the number of samples provided on each foil support. By means of the control system 16, 14, 18, the slide 20 can be displaced so that the optical reading beam becomes positioned to correspond with a first circumferential line of samples. Under such conditions, by rotating the support 7 through one revolution (by means of the control system 9, 10, 11), all the samples on the same circumferential line and present on foil supports located on the support are read successively.After one revolution of the support 7, the slide 20 is displaced in the radial direction (relative to the support 7) defined by the axis of the shaft 14, through a distance equal to the distance between adjacent strip samples of each foil support 12, and the samples located on the next circumferential line are then read. The slide 20 can be advanced during a short halt in the movement of the support 7 or while maintaining the continuous movement of the support.

In the embodiment described above, the bundles of optical fibres 26 and 30 are flexible in order to follow the relatively limited displacement of the slide 20. An embodiment is also possible in which a reading head including the assemblies 28 and 32 is fixed to the base, on which a slide carrying the support 7 is displaceable.

According to a possible modification, not shown, the reading system can be different from that indicated heretofore, which is used for reading transparency. In particular, a mixed bundle of illumination and reading fibres can be provided, reaching for example the arm 22 of the slide, in order to allow reading by reflection.

Fig. 3 shows a possible modified embodiment in which both the support and the slide carrying the reading head move continuously.

In this case, a disc-shaped support 107 is provided with seats 1 07A disposed so that the strip samples again substantially perpendicular to an intermediate radial direction, but with individual foil supports, that is the individual seats 107A, being located at a distance from the centre of the disc 107 which progressively varies, so that the strip samples are substantially aligned along a spiral with a pitch corresponding to the distance between adjacent samples of the same foil support. In this case, for each revolution of the disc 107, the slide 20 is advanced continuously at a distance equal to the pitch, and the reading process takes place with a continuous movement and during a number of revolutions equal to the number of samples carried by each foil support.At the end of this continuous and complete reading, the support 107 is halted in order to replace the samples, and the slide 20 is returned to the initial end of the path.

Fig. 4 shows diagrammatically a modified embodiment in which a fixed structure 1 20 is combined with the support 7 instead of a structure on a slide. This structure carries a number of optical reading heads equal to the number of strip samples provided on each foil support 12, in this case assumed fixed. The reading heads 1 22 are disposed in positions corresponding with the circumferential lines of the assembly of samples carried by the support 7. In this case, all the samples of any one foil support 1 2 are read simultaneously, and all the samples carried by the support are read during a single revolution of the support 7, or during a number of revolutions equal to the number of samples present on each support, there being provided change-over switching of the reading between the various reading heads.

In the further embodiment shown in Fig. 5, foil supports 212 are placed on the discshaped support 207 in a position perpendicular to the preceding examples, that is in a position such that the strip samples of each foil support 212 are parallel to an intermedi-, ate radial direction. In this case, a reading head 220 carries an assembly of optical fibres 225 which extends in a direction radial to the support 207 and is able to faithfully convey the image of the individual trace towards a linear matrix of photo-electric transducers.

Each strip sample is inspected instantaneously along its entire radial extension when it is located in the reading zone indicated by 225.

There is no relative radial movement between the reading head and the support, but only an angular movement of the support.

In the examples of Figs. 1 to 3, programming means---electronic or mechanical-can be disposed to enable the relative movements of the members of the apparatus to be matched to the number of samples present on each foil support and to the distance between the samples. The seats can also be adaptable to enable them to receive foil supports of different dimensions, of the support can be replaceable by a support of different dimen sions corresponding to the samples to be analysed.

It is also possible to use circular ring supports, that is continuous annular support on which strip samples are in this case located in a radial arrangement (analogous to the example of Fig. 5), for successive reading to the individual samples on the manner already described.

With the apparatus described, it is possible to obtain a more rapid reading of the individual samples, and thus a relatively large number of readings per unit of time, thereby increasing the productivity of each individual operator. In comparison with equivalent previously proposed apparatus, the overall size of the apparatus is less. Independent positioning for each foil support slide, can be attained by small magnets, so enabling any imperfect alignment between the membrane or foil support and the slide which has occurred during their joining together to be compensated. Also the sample support can be easily removed and replaced by another which has been previously arranged with samples.

Advantages attained by using optical fibres as described are as follows: reduction in the interferometric effects due to turbidity and diffused light (membranes not perfectly transparent); a "filter" effect on the environmental light; the possibility of placing the lamp and the photosensor at a distance from each other and from the sample; and an input-output guide effect, that is with limited entry of environmental light from the ends.

Claims (11)

1. Apparatus for the reading of samples, comprising a disc-shaped support carrying the samples, means for angularly moving said support, and reading means for reading the samples.

2. Apparatus as claimed in claim 1, in which each of the samples extends in the form of a strip with a chromatically variable sign in the direction of the strip length, wherein each of several groups of side-by-side strip samples are disposed on the support with the strip samples being positioned substantially perpendicularly to a substantially radial direction, adjacent groups of samples being disposed along a circular line on the support for reading during the rotation of the support.

3. Apparatus as claimed in claim 2, wherein the reading means comprises a reading head operative to read one strip sample at a time, and means operative to advance said head in a direction at least approximately corresponding to said substantially radial direction, the advancement being each time through a distance equal to the distance between the adjacent strip samples of any one group, for each revolution of the support.

4. Apparatus as claimed in claim 3, wherein the head is advanced stepwise, each stepwise advance being effected after each revolution of the support and during a short stoppage thereof.

5. Apparatus as claimed in claim 2 or claim 3, wherein the strip samples are disposed on said support in an array which substantially follows a spiral path and said head is advanced with continuous motion synchronously with the rotation of said support.

6. Apparatus as claimed in claim 2, wherein said reading means comprise several reading heads disposed in a substantially radial alignment and spaced apart to correspond to the strip samples of any one group for simultaneous and selective reading of said samples.

7. Apparatus as claimed in claim 1, wherein each of the samples is in the form of a strip disposed in a substantially radial position, and the reading means comprises a reading head of linear extension and arranged to simultaneously and selectively read all the zones of any one sample, and then of adjacent samples.

8. Apparatus as claimed in claim 1, claim 2, claim 3, claim 4, claim 6 or claim 7, wherein the support is arranged to receive side-by-side groups of samples, a respective foil support carrying each said group independently of the other groups.

9. Apparatus as claimed in any one of claims 1 to 7, wherein the support is arranged to receive a foil support in the form of a circular ring common to all the sample groups.

1 0. Apparatus for the opto-densitometric reading of samples, comprising a rotatable support arranged to carry the samples in strip form, and a reading system operative to read the successive samples during rotation of the support relative to the reading system.

11. Apparatus substantially as hereinbefore described with reference to Figs. 1 and 2, Fig. 3, Fig. 4, or Fig. 5 of the accompanying drawings.