Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
  • G01N27/416—Systems
  • G01N27/447—Systems using electrophoresis
  • G01N27/44704—Details; Accessories
  • G01N27/44717—Arrangements for investigating the separated zones, e.g. localising zones
  • G01N27/44721—Arrangements for investigating the separated zones, e.g. localising zones by optical means

Definitions

• the present invention relates to an arrangement in a gel electrophoresis apparatus having a laser which is adapted to emit a laser beam of a predetermined wavelength to excite at least one substance which is labelled with a fluorophore, and which is caused to migrate along a gel which is provided between two transparent plates, a detector which is located close to one of the plates to detect the fluorescence emitted upon excitation of the fluorophore, and an optical filter which is located between said one of the plates and the detector, and which is adapted to block light of said predetermined wavelength.
• fluorophore i.a. a carbocyanine based dye marketed under the trademark Cy5 by Biological Detection Systems, Inc., Pittsburg, PA, U.S.A.
• the dye Cy5 can be excited by means of a laser, e.g. a helium-neon laser, operating at a wavelength of 633 n , or a laser diode of a wavelength between 630 and 650 n .
• the fluorescence emitted upon excitation of the dye Cy5 will have a wavelength of between 650 and 720 nm with a maximum at about 670 nm.
• the object of the invention is to bring about an arrangement which makes it possible to eliminate the effect of this disturbing source.
• This is attained according to the invention in that the optical filter is adapted to block also the intrinsic fluorescence of the plates.
• Fig. 1 is a schematic cross-sectional view of a portion of an embodiment of a gel electrophoresis apparatus with an arrangement according to the invention
• Fig. 2 is a schematic diagram of fluorescence and filter characteristics in the embodiment shown in Fig. 1.
• Fig. 1 denotes an electrophoresis gel provided between two plates 2 and 3.
• the plates 2 and 3 are transparent and are preferably made of glass but can also be made of plastic.
• At least one substance 4, labelled with a fluorophore, e.g. the carbocyanine based dye Cy5, mentioned in the introduction, is adapted to migrate in a manner not shown under the influence of an electric field.
• a laser not shown, e.g. a helium-neon laser or a laser diode, is provided to supply into the gel 1, through one of the lateral edges of the gel 1, a laser beam of a predetermined wavelength to excite the fluorophore of the substance 4 migrating along the gel 1.
• Fig. 1 the substance 4 is schematically shown in the position where its fluorophore has been excited by the laser beam, not illustrated, going across the gel 1.
• a detector 5 e.g. a photo diode
• An optical filter 6 is provided between the detector 5 and the plate 3. According to the invention, the optical filter 6 is adapted to block not only light of the wavelength of the laser beam but also light originating from the intrinsic fluorescence of the glass plates 2 and 3 upon the excitation by the laser light.
• reference numeral 7 designates laser wavelength
• 8 is the characteristic of an optical filter according to the invention
• 9 designates fluorescence from a fluorophore
• 10 is fluorescence from glass plates.
• the fluorescence from the fluorophore detected by the detector 5 will exhibit a maximum at a wavelength of about 670 nm, while the maximum of the intrinsic fluorescence of the glass plates 2 and 3 will appear at a wavelength of about 770 nm.
• the optical filter 6 is designed as a band pass filter to block light of the laser wavelength as well as light originating from the intrinsic fluorescence of the glass plates 2 and 3.
• a number of detectors 5 and a number of optical filters 6 are provided to detect fluorophore labelled substances migrating along a corresponding number of parallel paths in the gel 1.
• the optical filter 6 is preferably dimensioned in such a manner that it exhibits a pass band characteristic having a center wavelength of 680 ⁇ 10 nm, a half-width of 40 ⁇ 5 nm and an attenuation which is greater than OD5 between 400 and 640 nm, and between 720 and 800 nm, and greater than OD3 between 800 and 1000 nm, as schematically apparent from the filter characteristic illustrated in Fig. 2.
• Such filters can be manufactured by i.a. Omega Optical, Inc., Brattleboro, VT, U.S.A..

Applications Claiming Priority (3)

Publications (1)

Family

ID=20396268

Family Applications (1)

Country Status (3)

Families Citing this family (6)

Family Cites Families (4)

• 1994
  • 1994-12-08 SE SE9404274A patent/SE9404274D0/xx unknown
• 1995
  • 1995-12-08 WO PCT/SE1995/001482 patent/WO1996018099A1/en not_active Application Discontinuation
  • 1995-12-08 EP EP95941309A patent/EP0805979A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events