EP0476792A1 — DNA sequencing

Claim 1

Independent Claim 31 words

Apparatus (10, A10, E10, 120, 122A, 122B) for sequencing DNA comprising: a gel electrophoresis slab (27,150); means (47A, 53A, 152, 151) for establishing electrical potential across gel electrophoresis slab (27); means

Claim 2

Dependent Claim 31 words

Apparatus (10, A10, E10, 120, 122A, 122B) for sequencing DNA comprising: a gel electrophoresis slab (27,150); means (47A, 53A, 152, 151) for establishing electrical potential across gel electrophoresis slab (27); means

Claim 3

Dependent Claim 119 words

(29A) for applying DNA samples at a plurality of locations for electrophoresing in a plurality of channels through said gel electrophoresis slab (27, 150); means for separating DNA samples in accordance with the size of DNA fragments in said gel electrophoresis slab (27, 150); means (142) for scanning the separated samples photoelectrically; said means (142) for scanning including a laser (170) and a sensor (172); characterized by a modulator (270); a detector (172) being positioned to absorb fluorescent light emitted by said DNA bands; said sensor (172) being applied to means for detecting pulses of light having the same pulse rate as laser light pulses, whereby background noise from the medium through which it is applied is discriminated against.

Claim 4

Dependent Claim 119 words

(29A) for applying DNA samples at a plurality of locations for electrophoresing in a plurality of channels through said gel electrophoresis slab (27, 150); means for separating DNA samples in accordance with the size of DNA fragments in said gel electrophoresis slab (27, 150); means (142) for scanning the separated samples photoelectrically; said means (142) for scanning including a laser (170) and a sensor (172); characterized by a modulator (270); a detector (172) being positioned to absorb fluorescent light emitted by said DNA bands; said sensor (172) being applied to means for detecting pulses of light having the same pulse rate as laser light pulses, whereby background noise from the medium through which it is applied is discriminated against.

Claim 5

Dependent Claim 37 words

Apparatus for sequencing DNA according to claim 1 characterized in that said modulator (270) is positioned between said laser (170) and said DNA bands, whereby said light from said laser (170) is pulsed at a predetermined rate.

Claim 6

Dependent Claim 43 words

Apparatus according to either claim 1 or 2 further characterized by means for eluting the bands from said gel (26A); said scanning means (142) being aligned with said elution means, whereby the bands are scanned after they are eluted from the gel (26A).

Claim 7

Dependent Claim 34 words

Apparatus according to any of claims 1-3 characterized by the scanning apparatus being aligned with said gel (27, 150), whereby the bands are scanned while still in the gel (150) but after being resolved.

Claim 8

Dependent Claim 77 words

Apparatus according to any of claims 1-3 characterized by means for separating the strands within at least one channel so that the bands of more mobile strands in the channel are fully resolved while some of the less mobile strands to be later formed into bands are unresolved in a continuous process such that at least 10 percent of the bands are fully resolved while the less mobile strands are yet unresolved into bands in the channel.

Claim 9

Dependent Claim 70 words

DNA sequencing apparatus according to any of claims 1-5 characterized by means (142) for scanning across said channels with light emitted from a laser in the band, incorporating at least the near infrared and infrared regions; means (172) for detecting fluorescent light emitted by said fluorescently marked strands in a band including at least said near infrared and infrared regions, whereby the time sequence of separated bands may be obtained.

Claim 10

Independent Claim 155 words

A method for sequencing DNA comprising: applying flourescently marked DNA samples at a plurality of locations for electrophoresing in a plurality of channels through a gel electrophoresis slab (27); establishing electrical potential across said gel electrophoresis slab (27, 150) wherein DNA samples are resolved in accordance with the size of DNA fragments in said gel electrophoresis slab into fluorescently marked DNA bands; scanning the separated samples photoelectrically with a laser (170) and a sensor (172) wherein the laser (170) scans with scanning light at a scanning light frequency within the absorbance spectrum of said fluorescently marked DNA samples and sensing light at the emission frequency of the marked DNA; characterized in that said light from said laser (170) is modulated at a predetermined modulation frequency and fluorescent light emitted by said DNA bands at said modulation frequency is detected, whereby background noise from the medium through which the light is transmitted may be discriminated against.

Claim 11

Independent Claim 155 words

A method for sequencing DNA comprising: applying flourescently marked DNA samples at a plurality of locations for electrophoresing in a plurality of channels through a gel electrophoresis slab (27); establishing electrical potential across said gel electrophoresis slab (27, 150) wherein DNA samples are resolved in accordance with the size of DNA fragments in said gel electrophoresis slab into fluorescently marked DNA bands; scanning the separated samples photoelectrically with a laser (170) and a sensor (172) wherein the laser (170) scans with scanning light at a scanning light frequency within the absorbance spectrum of said fluorescently marked DNA samples and sensing light at the emission frequency of the marked DNA; characterized in that said light from said laser (170) is modulated at a predetermined modulation frequency and fluorescent light emitted by said DNA bands at said modulation frequency is detected, whereby background noise from the medium through which the light is transmitted may be discriminated against.

Claim 12

Dependent Claim 24 words

A method according to claim 7 characterized in that light is modulated at a frequency within the band between 100 nz to 30 KH.

Claim 13

Independent Claim 40 words

A method according to either claims 7 or 8 characterized by eluting the bands from said gel (26A) wherein the scanning means is aligned with said elution means; and scanning the bands after they are eluted from the gel (26A).

Claim 14

Independent Claim 36 words

A method according to any of claims 7-8 characterized in that scanning means is aligned with said gel (27, 150) and the bands are scanned while still in the gel (27, 150) but after being resolved.

Claim 15

Independent Claim 78 words

A method according to any of claims 7-10 characterized in that the bands are resolved within at least one channel so that the bands of more mobile strands in the channel are fully resolved while some of the less mobile strands to be later formed into bands are unresolved in a continuous process such that at least 10 percent of the bands are fully resolved while the less mobile strands are yet unresolved into bands in the channel.

Claim 16

Independent Claim 75 words

A method according to any of claims 7-11 characterized by scanning across said channels with light emitted from a laser; and detecting fluorescent light emitted by said fluorescently marked strands, whereby the time sequence of separated bands may be obtained with a laser emitting light in the band incorporating at least the near infrared and infrared regions and said detector responding to light in a band including at least said near infrared and infrared regions.

DNA sequencing

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