Abstract: To sequence DNA automatically, DNA marked with near infrared fluorescent dyes are electrophoresed in a plurality of channels through a gel electrophoresis slab wherein the DNA samples are resolved in accordance with the size of DNA fragments in the gel electrophoresis slab into fluorescently marked DNA bands. The separated samples are scanned photoelectrically with a laser diode and a sensor, wherein the laser scans with scanning light at a scanning light frequency within the absorbance spectrum of said fluorescently marked DNA samples and light is sensed at the emission frequency of the marked DNA. The light is modulated from said laser 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 is discriminated against.

Abstract: Provided are water-dissipatable, sulfo-containing polyesters and polyester-amides having copolymerized therein thermally stable near infrared flourophoric compounds. The polymers are useful in coating or ink compositions, which are in turn useful for marking articles for identification/authentication purposes. Also provided is a method for invisibly marking such articles and a method for detecting and sorting articles by utilizing the near infrared flourophoric ink or coating compositions.

Abstract: Provided are water-dissipatable, sulfo-containing polyesters and polyester-amides having copolymerized therein thermally stable near infrared flourophoric compounds. The polymers are useful in coating or ink compositions, which are in turn useful for marking articles for identification/authentication purposes. Also provided is a method for invisibly marking such articles and a method for detecting and sorting articles by utilizing the near infrared flourophoric ink or coating compositions.

Abstract: To sequence DNA automatically, DNA marked with near infrared fluorescent dyes are electrophoresed in a plurality of channels through a gel electrophoresis slab wherein the DNA samples are resolved in accordance with the size of DNA fragments in the gel electrophoresis slab into fluorescently marked DNA bands. The separated samples are scanned photoelectrically with a laser diode and a sensor, wherein the laser scans with scanning light at a scanning light frequency within the absorbance spectrum of said fluorescently marked DNA samples and light is sensed at the emission frequency of the marked DNA. The light is modulated from said laser 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 is discriminated against.

Abstract: A system for stabilizing the arc in a DC arc lamp. An AC signal is superimposed on the DC power source of the lamp to cause small regular fluctuations in the arc. The small fluctuations prevent large fluctuations while the small regular fluctuations may be averaged to obtain a constant average value. The average is taken over 5 to 10 periods of the AC signal to produce a constant average signal with a very small standard deviation.

Abstract: A gas producing electrolytic cell for portable devices comprising a vessel, an electrolyte, a cap, a gas space, channel labyrinths, a separating wall and contacts. The channel labyrinths eliminate the outflow of the electrolyte from the cell in its overturned position, tender the return of electrolyte to the vessel, to the original level possible. The contacts can be inundated by the electrolyte and in this way an outer electric circuit can be closed for cutting out the stream of electrolyse and for signalizating the overturned position of the cell.

Abstract: Process and apparatus for the determination of the total organic substance content of gases by a flame ionization detector, respectively comprising the steps and means for allowing components of the gas to be analyzed to diffuse through a pore-free polymeric membrane having a permeability coefficient that exceeds 10.sup.-7 Ncm.sup.3.cm/sec.cm.sup.2.Hgcm. related to the total organic substance contained in the gas, leading the gas components into a flame of another gas that contains hydrogen, passing the burning hydrogen-containing gas along one side of the membrane at a flow rate of max. 25 cm.sup.3 /min.