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Patent Issued for Apparatus for Fabricating and Optically Detecting Biochip

August 20, 2014



By a News Reporter-Staff News Editor at Journal of Engineering -- Samsung Electronics Co., Ltd. (Suwon-Si, KR) has been issued patent number 8796011, according to news reporting originating out of Alexandria, Virginia, by VerticalNews editors.

The patent's inventor is Cho, Seong-ho (Gwacheon-si, KR).

This patent was filed on August 21, 2009 and was published online on August 5, 2014.

From the background information supplied by the inventors, news correspondents obtained the following quote: "One or more exemplary embodiments relate to an apparatus for fabricating a biochip by using a photolithographic method without using a mask, and for optically detecting the biochip so as to read the biochip.

"A biochip is a biometric device made by combining biogenic organic materials such as enzymes, peptides, proteins, antibodies, and deoxyribonucleic acids ('DNAs') of living creatures, microorganisms, and cells, organs, and nerves of animals and plants into a microchip similar to a semiconductor chip. In particular, a DNA chip is a device for detecting DNAs. The DNA chip is made by arranging several hundred DNAs to ten million DNAs having different base sequences, of which functions in a cell are clarified, within a small space on a substrate. Furthermore, the DNAs are arranged in a single spiral shape instead of a double spiral shape on the substrate. The substrate can be a glass substrate or a semiconductor substrate for example. A collection of single spiral shaped DNAs having the same base sequence is generally referred to as a spot and nearly twenty to hundred bases are connected to form a single spot.

"When genetic material of a sample is dropped onto such a DNA chip, only genes corresponding to a specific spot, i.e., genes having a complementary sequence to a base sequence of the specific spot, are combined with the corresponding spot. Furthermore, genes that are not combined with spots in the DNA chip are washed away. Functions of base sequences of spots arranged on a DNA chip are already known, and thus genetic information of the sample can be easily obtained by identifying spots combined with genes on the DNA chip. Accordingly, aspects of unique genetic expressions or mutations in a specific cell or a tissue can be analyzed relatively fast by using the DNA chip. Furthermore, the DNA chip can also be used in massive analysis of genetic expressions, single nucleotide polymorphism and copy number variation in a gene, a pathogenic bacteria infection test, an antibiotic-resistance test, research on biological reactions with respect to environmental factors, food safety inspection, identification of criminals, development of new drugs, and medical inspection of animals and plants.

"Such a biochip can be fabricated by stacking DNA bases such as adenine (A), guanine (G), cytosine (C), and thymine (T) in different sequences on spots of the biochip, for example, twenty to hundred times. A very precise fabricating method is utilized to form several ten million of different spots in a single biochip with exact base sequences. A representative method of fabricating a biochip is a photolithographic method which is the same method used for fabricating a semiconductor. In the photolithographic method, a biochip except for an area for reacting with a specific base is covered by a mask and light is projected onto the biochip. In this exemplary embodiment, all bases used for reaction are combined with a photolabile material such that the bases cannot combine with each other. However, when light is projected, the photolabile material is decomposed from the bases and thus a base onto which light is projected can combine with another base. Accordingly, the specific base can be combined with bases that are not covered by the mask and are exposed to light. In the photolithographic method, although the biochip can be precisely fabricated, a fabricating time is relatively long and a fabricating cost is relatively high because the lithography equipment is relatively expensive and a large number of masks corresponding to about four times of the number of stacked bases are used.

"Meanwhile, when a sample is analyzed, various methods for identifying spots in a DNA chip, which are combined with genes of the sample, have been suggested. A fluorescent light detection method is a representative example of the suggested methods. In the fluorescent light detection method, a base including a fluorescent material for emitting light of a specific color when excited by excitation light is combined with genetic material of the sample. The genetic material of the sample is dropped onto a DNA chip and then a fluorescent image obtained by projecting excitation light onto the DNA chip is analyzed, thereby indentifying spots combined with genes of the sample.

"In general, a photodetector for obtaining a fluorescent image by projecting excitation light onto a DNA chip obtains a fluorescent image by detecting a DNA chip in pixels of approximately 0.1 .mu.m to 10 .mu.m. Such a basic detecting unit is referred as a segment, and a single spot is formed of several segments to several tens of segments (e.g., 32 segments). A segment is a basic scanning unit in a spot detection method and a panel formed of several hundred spot arrays to several thousand spot arrays (e.g., 5,000 spot arrays) is a basic scanning unit in an image detection method. Generally, the spot detection method uses a photomultiplier tube ('PMT') as the photodetector and the image detection method uses a charge-coupled device ('CCD'), a complementary metal-oxide-semiconductor ('CMOS') image sensor ('CIS'), or the like as the photodetector. A bio-chip scanner, i.e., a fluorescence detector, may read a DNA chip by scanning each segment or panel in the DNA chip.

"However, since a process of fabricating a DNA chip is separated from a process of analyzing a sample, and an apparatus for fabricating the DNA chip is separated from a fluorescence detector for reading the DNA chip, exposure to an external environment is unavoidable when the DNA chip is reprocessed, stored, and used to analyze a sample, which degrades a reliability of the DNA chip."

Supplementing the background information on this patent, VerticalNews reporters also obtained the inventor's summary information for this patent: "One or more exemplary embodiments include an apparatus for fabricating a biochip such as a deoxyribonucleic acid ('DNA') chip by using a photolithographic method without using a mask, and directly analyzing a sample by optically detecting the DNA chip.

"One or more exemplary embodiments include an apparatus for fabricating and optically detecting a biochip, and monitoring a process of fabricating the biochip.

"One exemplary embodiment may include an apparatus for fabricating a biochip, the apparatus including a reaction chamber which encapsulates the biochip to be sealed from an external environment; an exposure system which has a light source and a spatial light modulator ('SLM'), the SLM receives light from the light source and forms an optical image utilizing the received light, the optical image being received by the biochip; and a detection system which detects light proceeding from the biochip.

"In one exemplary embodiment, the SLM may be a reflective SLM.

"In one exemplary embodiment, the apparatus may further include an optical path changing unit which provides the light emitted from the light source to the SLM, and provides light reflected from the SLM to the reaction chamber, and provides light proceeding from the reaction chamber to the detection system.

"In one exemplary embodiment, the optical path changing unit may include a polarizing beam splitter which is disposed between the light source and the SLM; a polarizer which is disposed between the light source and the polarizing beam splitter; and a quarter-wavelength ('.lamda./4') plate which is disposed between the polarizing beam splitter and the SLM.

"In one exemplary embodiment, the exposure system may further include a light diffusion device which is disposed between the light source and the polarizer; a lens device or a mirror device which is disposed between the .lamda./4 plate and the SLM; a distortion correction device which is disposed between the polarizing beam splitter and the reaction chamber; and a projection optical system which is disposed between the distortion correction device and the reaction chamber.

"In one exemplary embodiment, the distortion correction device may include a deformable mirror having a reflective surface which is deformable in response to at least one of mechanical and electrical manipulation for correcting distortion of an optical image.

"In one exemplary embodiment, the detection system may be disposed such that the detection system faces one of light exit surfaces of the polarizing beam splitter in order to detect an optical image proceeding from the reaction chamber through the polarizing beam splitter.

"In one exemplary embodiment, the optical path changing unit may further include an additional .lamda./4 plate which is disposed between the polarizing beam splitter and the reaction chamber.

"In one exemplary embodiment, the detection system may be disposed proximate to the reaction chamber along a direction in which light proceeds, in order to detect an optical image which is transmitted through the reaction chamber and the biochip.

"In one exemplary embodiment, the apparatus may further include an additional distortion correction device which is disposed between the reaction chamber and the detection system.

"In one exemplary embodiment, the SLM may be a transmissive SLM.

"In one exemplary embodiment, the exposure system may further include a light diffusion device and at least one of a lens device and a mirror device which are sequentially disposed between the light source and the SLM along a direction where light proceeds; and a distortion correction device and a projection optical system which are sequentially disposed between the SLM and the reaction chamber along a direction where light proceeds.

"In one exemplary embodiment, the apparatus may further include an optical path changing unit which provides light emitted from the light source to the reaction chamber, and provides light proceeding from the reaction chamber to the detection system.

"In one exemplary embodiment, the optical path changing unit may include a polarizing beam splitter which is disposed between the light diffusion device and at least one of the lens device and the mirror device; a polarizer which is disposed between the light diffusion device and the polarizing beam splitter; and a .lamda./4 plate which is disposed between the polarizing beam splitter and the at least one of the lens device and the mirror device.

"In one exemplary embodiment, the light source of the exposure system may include a first light source which emits exposure light which is received by an optical multiplexer; and a second light source which emits excitation light which is received by an optical multiplexer, and the optical multiplexer selectively transmits or blocks one of the exposure light emitted from the first light source and the excitation light emitted from the second light source.

"In one exemplary embodiment, the apparatus may further include an optical fiber which is disposed between the first light source and the optical multiplexer and further between the second light source and the optical multiplexer.

"In one exemplary embodiment, the detection system may include an excitation light absorption filter, at least one of an imaging lens and an imaging mirror, and a photodetector which are sequentially disposed along a direction in which light proceeds.

"In one exemplary embodiment, the excitation light absorption filter may be separated from an optical path when the biochip is fabricated.

"In one exemplary embodiment, the photodetector may be formed of an array including a plurality of micro pixels, and may include one of a photomultiplier tube ('PMT'), a charge-coupled device ('CCD'), and a complementary metal-oxide-semiconductor ('CMOS') image sensor ('CIS')."

For the URL and additional information on this patent, see: Cho, Seong-ho. Apparatus for Fabricating and Optically Detecting Biochip. U.S. Patent Number 8796011, filed August 21, 2009, and published online on August 5, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8796011.PN.&OS=PN/8796011RS=PN/8796011

Keywords for this news article include: Biochips, DNA Research, Semiconductor, Bionanotechnology, Nanobiotechnology, Emerging Technologies, Samsung Electronics Co. Ltd..

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Source: Journal of Engineering


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