Electrophoresis pattern reading system of fluorescence type

Abstract

An electrophoresis pattern reading system of fluorescent type is comprised of a detachable migration unit comprising a gel functioning as a base for electrophoresis and a gel-supporting body for supporting the gel; an electrophoresis unit, to which the migration unit is mounted, for performing electrophoresis by applying migrating voltage to the gel to which a sample labeled with a fluorescent substance is added; and a reading unit including an instrumentation subunit for reading an electrophoresis pattern, to which the migration unit is mounted after electrophoresis and which receives fluorescence emitted from the fluorescent substance of the sample on the gel upon application of light to the gel. For example, a plurality of the migration units and the electrophoresis units are provided, and each of the plural migration units are mounted to one reading unit in order after electrophoresis has been performed with the respective electrophoresis units for a long period of time, thereby reading the electrophoresis pattern in a short period of time.

What is claimed is: 
     
       1. An electrophoresis pattern reading system of fluorescence-detection type, useful for analyzing a gel-based sample, the sample being labeled with a fluorescent substance that fluoresces upon application of light thereto, comprising: a detachable migration unit comprising a gel functioning as a base for a sample to be analyzed by electrophoresis and a gel-supporting body for supporting the gel;   an electrophoresis unit, to which the migration unit is detachably mounted, for performing electrophoresis by applying migrating voltage to the gel to which the sample labeled with a fluorescent substance is added; and   a reading unit physically separate from the electrophoresis unit for reading an electrophoresis pattern, the reading unit including means for detachably mounting the migration unit detached from and apart from the electrophoresis unit after electrophoresis, and said reading unit having means for passing light to the detachably mounted migration unit and for receiving fluorescence emitted from the fluorescent substance of the sample on the gel upon application of the light.   
     
     
       2. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 1, wherein a plurality of electrophoresis units is provided for each reading unit. 
     
     
       3. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 1, said means for passing light comprising a spot light source for generating light for exciting fluorescence of the fluorescent substance, a scanning means for scanning light from the spot light source in a direction substantially parallel to the direction of electrophoresis by radiation upon the gel, and a reading section having a light-receiving subsection for receiving fluorescence from the fluorescent substance. 
     
     
       4. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 3, wherein the light-receiving subsection comprises a one-dimensional image sensor, wherein the direction in which the light is received is substantially parallel to the direction of electrophoresis. 
     
     
       5. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 3, wherein said means for passing light and said scanning means produces the scanning light of a width in the direction perpendicular to the direction of electrophoresis that is extended on the basis of the reading width of the irradiated area in the direction .Iadd.substantially .Iaddend.parallel to the direction of electrophoresis. 
     
     
       6. An electrophoresis pattern reading system as claimed in claim 3, wherein the scanning means includes a concave lens for modulating the light from the spot light source. 
     
     
       7. An electrophoresis pattern reading system as claimed in claim 6, wherein the concave lens is arranged to modulate the light from the spot light source to enlarge reading size with respect to a direction substantially perpendicular to the direction of electrophoresis. 
     
     
       8. An electrophoresis pattern reading system as claimed in claim 3, wherein the scanning means includes a convex lens for modulating the light from the spot light source. 
     
     
       9. An electrophoresis pattern reading system as claimed in claim 8, wherein the convex lens is .[.disclosed.]. .Iadd.disposed .Iaddend.substantially parallel to the direction of electrophoresis. 
     
     
       10. An electrophoresis pattern reading system as claimed in claim 1, wherein the sample comprises a nucleic acid. 
     
     
       11. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 2, said means for passing light comprising a spot light source for generating light for exciting fluorescence of the fluorescent substance, a scanning means for scanning light from the spot light source in a direction substantially parallel to the direction of electrophoresis by radiation upon the gel, and a reading section having a light-receiving subsection for receiving fluorescence from the fluorescent substance. 
     
     
       12. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 11, wherein the light-receiving subsection comprises a one-dimensional image sensor, wherein the direction in which the light is received is substantially parallel to the direction of electrophoresis. 
     
     
       13. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 11, wherein said means for passing light and said scanning means produces the scanning light of a width in .[.the.]. .Iadd.a .Iaddend.direction perpendicular to the direction of electrophoresis that is extended on the basis of .[.the.]. .Iadd.a .Iaddend.reading width of .[.the.]. .Iadd.an .Iaddend.irradiated area in the direction .Iadd.substantially .Iaddend.parallel to the direction of electrophoresis. 
     
     
       14. An electrophoresis pattern reading system as claimed in claim 11, wherein the scanning means includes a concave lens for modulating the light from the spot light source. 
     
     
       15. An electrophoresis pattern reading system as claimed in claim 14, wherein the concave lens is arranged to modulate the light from the spot light source to enlarge reading size with respect to a direction substantially perpendicular to the direction of electrophoresis. 
     
     
       16. An electrophoresis pattern reading system as claimed in claim 11, wherein the scanning means includes a convex lens for modulating the light from the spot light source. 
     
     
       17. An electrophoresis pattern reading system as claimed in claim 16, wherein the convex lens is .[.disclosed.]. .Iadd.disposed .Iaddend.substantially parallel to the direction of electrophoresis. 
     
     
       18. An electrophoresis pattern reading system as claimed in claim 2, wherein the sample comprises a nucleic acid. 
     
     
       19. A method for reading an electrophoresis pattern of fluorescence-detection type, comprising: the step of pouring a sample into a gel in a migration unit, the step of mounting the migration unit in an electrophoresis unit, thereafter the step of performing electrophoresis of the sample, the step of thereafter removing the migration unit with the electrophoresed sample from the electrophoresis unit, the step of mounting the removed migration unit with the electrophoresed sample in a reading unit, and the step of reading the electrophoresis pattern of the electrophoresed sample in the migration unit by the reading unit.   
     
     
       20. A method for reading an electrophoresis pattern of .[.fluorescent.]. .Iadd.fluorescence-detection .Iaddend.type as claimed in claim 19, further comprising the step of providing a plurality of the migration units and a plurality of the electrophoresis units, wherein the step of mounting the migration unit in the reading unit is carried out serially for each of the plurality of the migration units in a common reading unit. 
     
     
       21. A method for reading an electrophoresis pattern of fluorescence-detection type as claimed in claim 19, wherein a direction substantially parallel to a direction of electrophoresis is set as a first direction and a direction perpendicular to the direction of electrophoresis is set as a second direction, and the step of reading the electrophoresis pattern includes the step of defining a pixel size having a longer dimension in the first direction than in the second direction. 
     
     
       22. A method for reading an electrophoresis pattern of .[.fluorescent.]. .Iadd.fluorescence-detection .Iaddend.type as claimed in claim 21, wherein the step of reading the electrophoresis pattern includes the step of obtaining data of a pattern of distribution of the .[.fluorescent substance.]. .Iadd.electrophoresed sample.Iaddend., and thinning out the data by at least one pixel in the second direction. 
     
     
       23. A method for reading an electrophoresis pattern .Iadd.of fluorescence-detection type .Iaddend.as claimed in claim 19, wherein said .[.step of pouring uses the.]. sample comprises a nucleic acid. 
     
     
       24. A method for reading an electrophoresis pattern of fluorescence-detection type, comprising: (a) pouring a plurality of samples one each into a like plurality of gels one each .[.into.]. .Iadd.in .Iaddend.a like plurality of migration units;   (b) mounting each migration unit one each in a like plurality of electrophoresis units;   (c) thereafter performing electrophoresis of each sample;   (d) thereafter removing one migration unit with its electrophoresed sample from a first one of the plurality of electrophoresis units;   (e) mounting the removed migration unit with its electrophoresed sample in a reading unit;   (f) reading the electrophoresis pattern of the .[.electrophoresis.]. .Iadd.electrophoresed .Iaddend.sample in the migration unit by the reading unit; and   (g) repeating the steps (d) through (f) for each remaining electrophoresed sample, and using the same reading unit for each reading step. .Iadd.   
     
     
       25.  An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 1, wherein said means for receiving fluorescence further comprises means for scanning the sample with the light as excitation light in one axial direction which is a direction nearly parallel or nearly perpendicular to the direction of electrophoresis, and means for moving the sample in a direction perpendicular to the one axial direction. .Iaddend..Iadd.26. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 25, wherein said means for scanning provides said one axial direction substantially parallel to a direction of electrophoresis of the sample. .Iaddend..Iadd.27. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 1, wherein said means for receiving fluorescence has an optical axial extending in a direction different from an optical axis of said means for passing light. .Iaddend..Iadd.28. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 1, wherein said means for passing light irradiates the fluorescent substance with exciting light in a plane at a constant optical angle of incidence with respect to a surface defined by the electrophoresis pattern. .Iaddend..Iadd.29. An electrophoresis pattern reading system of fluorescence-detection type as claimed in claim 1, wherein said means for passing light and said means for receiving light are located on a common side of and spaced from a surface defined by the electrophoresis pattern. .Iaddend..Iadd.30. An electrophoresis pattern reader for reading an electrophoresis pattern defining a sample plane in a sample that has been labeled with a fluorescent substance that fluoresces at a second wavelength upon application of light thereto at a first wavelength, comprising: a sample holder for detachably holding the sample apart from any electrophoresis unit and further defining the sample plane;   a light source emitting the light of the first wavelength to the sample in a light source direction angularly intersecting the sample plane;   a scanner for scanning by moving the light emitted by the light source and the sample holder relative to each other in a first direction, which is a direction nearly parallel or nearly perpendicular to the direction of electrophoresis, in the sample plane and in a second direction in the sample plane at a perpendicular angle with respect to the first direction, to irradiate the fluorescent substance, to excite the fluorescent substance and to produce fluorescence at the second wavelength;   the light source direction being at an angle of incidence with respect to the sample plane sufficient to transmit the light to the fluorescent substance;   a collector for collecting the fluorescence at the second wavelength along an emittance direction at an angle of emittance relative to the sample plane, and including a spectral filter for rejecting light of the first wavelength and passing light of the second wavelength;   the light source forming the light source direction and the collector forming the emittance direction to intersect each other at a scanning location on the sample; and   a sensor for sensing the fluorescence at the second wavelength after the fluorescence is collected and filtered by said collector, over a period of time for each of a plurality of the scanning locations, to produce a correlated electrical analog signal having an analog value proportional to quantity of the fluorescence at the second wavelength received during the   
     
     
        period of time. .Iaddend..Iadd.31.  An electrophoresis pattern reader according to claim 30, including an analog to digital converter for converting the analog value of the analog signal to a digital value; and means for outputting a scan of the digital values correlated to the   
     
     
        scanning of the sample. .Iaddend..Iadd.32.  An electrophoresis pattern reader according to claim 30, wherein said scanner provides the first direction parallel to a direction of electrophoresis in the electrophoresis pattern and provides the second direction substantially perpendicular to the first direction. .Iaddend..Iadd.33. An electrophoresis pattern reader according to claim 30, further including a mirror for reflecting fluorescence of the second wavelength to said collector. .Iaddend..Iadd.34. An electrophoresis pattern reader according to claim 30, wherein said light source is a laser. .Iaddend..Iadd.35. An electrophoresis pattern reader according to claim 31, wherein said scanner includes a vibrating mirror, said collector includes a collector lens and a condenser; wherein said sensor is a photomultiplier for photoelectrical conversion; and   further including an amplifier between said sensor and said analog to digital converter. .Iaddend..Iadd.36. An electrophoresis pattern reader according to claim 30, further including means for changing scanning speed by varying an exciting light spot size at the scanning location through changing the angle of incidence of the exciting light to change the ratio of exciting light spot size on the electrophoresis pattern in said first direction and said second direction. .Iaddend..Iadd.37. An electrophoresis pattern reader according to claim 30, wherein said scanner moves the light emitted by the light source in only one scanning plane as one dimensional scanning in the first direction and relatively moves the light source and the sample in the second direction while maintaining substantially constant the angle of incidence defined by the angle of intersection between the light source plane and the sample plane;   said sensor spatially separating light from the surface of the sample of the fluorescence from scattered light from the light source and the sample plane;   said sensor producing the analog signal with spatially separate electrical components separated according to the spatially separate light components; and   means for extracting only the electrical component of the fluorescence from other electrical components on the basis of the spatially separate electrical components for improving a signal to noise ratio.   
     
     
        .Iaddend..Iadd.38.  An electrophoresis pattern reader according to claim 37, wherein the angle of intersection between the light source plane and the sample plane is sufficiently smaller than 90° to physically separate scattered/reflected light to be spaced from an optical axis of the sensor wherein the greatest intensity of received fluorescence is detected, as viewed at the sensor. .Iaddend..Iadd.39. An electrophoresis pattern reader according to claim 38, wherein the scattered/reflected light produces intensity peaks at said sensor physically spaced from intensity peaks of the received fluorescence, disposed parallel to the sample plane. .Iaddend.