KR100759914B1 - Bio chip scanner having a function of adjusting focus - Google Patents

Abstract

Disclosed is a biochip scanner having a focus control function. The light source unit irradiates light of a predetermined wavelength to a detection point. The transfer unit transfers the biochip so that light is irradiated to a plurality of reference points spaced a predetermined distance from the biochip. The detector is located above the detection point, and detects light irradiated to each reference point and outputs a plurality of images corresponding to each reference point. The focusing unit sets the distance corresponding to the average value of the light intensity acquired from each image corresponding to each reference point input from the detector as the focal length, and moves the detector upward or downward according to the set focal length to the biochip. Adjust the corresponding focus. According to the present invention, since autofocus control is possible for each sample on a biochip having a different surface gradient, it is possible to detect whether the gene is expressed more accurately.

Biochip, Scanner, Focusing, Gene, Hybridization

Description

Bio chip scanner having a function of adjusting focus

1 is a view showing a conventional biochip scanner,

2 is a block diagram showing a detailed configuration of a biochip scanner according to the present invention;

3 shows a detailed configuration of an embodiment of a biochip scanner according to the present invention;

4 is a block diagram showing a detailed configuration of a focusing unit;

5 is a view showing an image of a reference point detected by the reference point detection unit of the focusing unit;

6 is a diagram showing the configuration of an embodiment of a multi-channel biochip scanner;

7 is a block diagram showing a detailed configuration of a light compensation device which can be applied to a biochip scanner according to the present invention;

8 is a diagram illustrating a configuration of an embodiment of a biochip scanner equipped with a light compensation device.

The present invention relates to a biochip scanner, and more particularly, to a biochip scanner for detecting a human disease by detecting light reflected from the biochip.

Biochip refers to the accumulation of biomolecules such as DNA and protein on a small substrate made of glass, silicon, nylon, or the like. Typically, hundreds to tens of thousands of DNA arrays are arranged on the surface of a biochip, and the DNA arrays arranged on the biochip are prepared based on human genetic information elucidated by the human genome plan. The target DNA array, previously labeled with fluorescent material, is hybridized with the probe DNA array placed on the surface of the biochip. When the probe DNA array is combined with the target DNA array, the fluorescent material labeled on the target DNA array emits light. Therefore, the biochip scanner can be used to detect the expression of genes by detecting the light emitted from the fluorescent material. Such biochips are applied to a wide variety of fields such as gene / protein function analysis, new drug development, animal and plant quarantine, forensics, genetic mutation detection, drug sensitivity testing, antibiotic resistance testing, and pathogen detection.

Methods of analyzing and diagnosing biochips include optical methods and electrochemical methods, and optical methods are the main measurement methods. In the optical method, a fluorescent material reacting to a specific wavelength is coated on a target DNA to be analyzed and hybridized with a probe DNA having a base complementary to the target DNA. Next, the biochip scanner irradiates excitation light having a specific wavelength to a region where the target DNA and the probe DNA exist on the biochip, and then detects light having a specific wavelength emitted from the fluorescent material. In this way, if the fluorescent material present in the biochip receives light of a specific wavelength, the internal energy rises and then returns to a low energy state, and thus the hybridization can be detected by using the property of emitting light having a wavelength longer than the excitation light. . A biochip scanner is a device used for irradiation of excitation light and detection of emitted light.

1 is a diagram illustrating a conventional biochip scanner.

Referring to FIG. 1, a conventional biochip scanner includes a glass holder 20, a light source 30, a transfer unit 40, and a detector 50.

The glass holder 20 is equipped with a biochip 10 in which a target DNA labeled with a fluorescent material and a probe DNA are hybridized to each other. The light source unit 30 generates excitation light having a wavelength capable of emitting a fluorescent material to irradiate light onto the target DNA on the biochip 10. The transfer unit 40 transfers the biochip 10 from the glass holder unit 20 in the vertical or horizontal direction. The detector 50 detects light emitted from the fluorescent material and measures the amount of fluorescent expression of DNA.

The biochip scanner is classified into two types according to the light source used in the light source unit 30. The biochip scanner uses a white light such as xenon or a metal halide lamp, a YAG laser, and a He-Ne laser. It is classified into the laser system using a laser etc. In addition, an image element including a CCD camera, a photomultiplier tube (PMT), and the like are used as a sensor for detecting the light emitted from the fluorescent material by the detector 50.

In the case of using white light, a color filter transmitting only a specific wavelength to select only a wavelength suitable for the fluorescent material to be detected among the light generated from a white light source and a refractive lens to strongly irradiate light to a large area to be scanned To control the excitation light using a light source, an area sensor such as a CCD should be adopted to obtain an image. Existing biochip scanners using white light take up a lot of space because they use a lamp, and have a disadvantage in that the light efficiency actually used is lowered because only light of a specific wavelength is selected. In addition, because of the need for a lot of additional equipment to cool the heat generated from the lamp and to collect the generated light, the weight of the equipment is increased, and a lot of time is also spent on processing and assembly. As a result, the use of laser-based biochip scanners is gradually increasing.

In order to accurately detect whether the gene is expressed using the biochip scanner, the distance between the detector 50 and the sample (ie, hybridization region of the target DNA and the probe DNA) arranged in a matrix form on the biochip 10 ( That is, the focal length) needs to be properly adjusted. However, in the conventional biochip scanner described above, there is an inconvenience that a user must manually manipulate the distance between the detector 50 and the biochip 10 based on the image detected by the detector 50. Furthermore, when the surface of the biochip 10 is not perpendicular to the detector 50, a situation arises in which the focus is not focused on the sample at another point even if the focus is correctly set at the sample at a certain point.

An object of the present invention is to provide a biochip scanner capable of adjusting the focal length with the biochip.

In order to achieve the above technical problem, a biochip scanner according to the present invention includes a light source unit for irradiating light of a predetermined wavelength to a detection point; A transfer unit configured to transfer the biochip so that the light is irradiated to a plurality of reference points spaced a predetermined distance from the biochip; A detection unit positioned above the detection point and detecting a light irradiated to each reference point and outputting a plurality of images corresponding to each reference point; And setting a distance corresponding to an average value of the intensity of light acquired from each image corresponding to each reference point received from the detector as a focal length, and moving the detector upward or downward according to the set focal length. And a focusing unit for adjusting a focus corresponding to the biochip.

This enables automatic focus control of each sample on the biochip having different surface gradients, thereby more accurately detecting whether the gene is expressed.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the biochip scanner according to the present invention.

2 is a block diagram showing a detailed configuration of a biochip scanner according to the present invention, Figure 3 is a view showing a detailed configuration of an embodiment of a biochip scanner according to the present invention.

2 and 3, the biochip scanner according to the present invention includes a mounting unit 220, a light source unit 230, a transfer unit 240, a detection unit 250, a filter unit 260, a focusing unit 270, and a control unit. 280 is provided.

The mounting unit 220 is mounted with a biochip 200 hybridized with a target DNA and a probe DNA labeled with a fluorescent material. The transfer unit 240 transfers the mounting unit 220 from the mounting point to the detection point. The conveying part 240 is movable in each axial direction shown in the figure, and the conveying direction from the mounting point to the detecting point is selected from the X-axis direction or the Y-axis direction depending on the configuration of the apparatus. In addition, when the mounting unit 220 reaches the detection point, the transfer unit 240 may move vertically by a position determined in the Z-axis direction and between the sample on the biochip 200 mounted on the mounting unit 220 and the end of the detection unit 250. Make sure that the distance matches the preset focal length.

The light source unit 230 irradiates a sample arranged on the biochip 200 with light or a laser beam having a predetermined wavelength. The light source unit 230 is installed to have a predetermined angle toward the mounting unit 220 from the side of the detection unit 250 to irradiate the excitation light to the biochip 200 fixed to the mounting unit 220. The light emitting source of the light source unit 230 may vary depending on the fluorescent material labeled on the DNA of the biochip. When FITC is used as the fluorescent material, 488 nm-laser may be used, and APC (Allophyco-cyanin) may be used as the fluorescent material. When used as a 633nm He-Ne laser or a laser diode can be used. At this time, employing a laser diode as a light source has the advantage that the device can be further miniaturized.

The light source unit 230 includes a light source 231, first and second reflection mirrors 232 and 233, a waveguide 234, a third reflection mirror 235, and a condenser lens 236. Each of the components 231, 232, 233, 234, 235, and 236 provided in the light source unit 230 is disposed on a single panel P. FIG. The light emitted from the light source 231 becomes more uniform as it passes through the waveguide 234 after the path is changed by the first and second reflection mirrors 232 and 233, and then the path is caused by the third reflection mirror 235. After the change, the light is directed to the condenser lens 236. The condenser lens 236 allows most of the energy of the light to be irradiated onto the desired sample. Each of the reflection mirrors 232, 233, and 235 provided in the light source unit 230 changes the path of light to a desired shape, thereby contributing to miniaturization of the size of the light source unit 230.

The detector 250 is positioned above the mounting unit 220 to detect fluorescence generated by the biochip 200 mounted on the mounting unit 220. The detector 250 detects the fluorescence emitted from the biochip 200 to form an image, and the detector 250 may be a light augmented tube (PMT) or a CCD camera. CCD cameras include linear image elements and area image elements, including time delayed integration (TDI) sensors. The detector 250 processes the acquired image and outputs an analysis result. Such an image processing process and an analysis process may be performed by a separate analysis device rather than the detection unit 250. For example, in the case of the DNA chip analysis device, the Cy3 ™ obtained by the detection unit 250 using a DNA chip analysis software. Image data having a fluorescence intensity of Cy5 ™ is digitized. The quantified data can be visually variously expressed by the DNA chip analysis software such as scatter ratio, circle graph, image overlap, and the like (mRNA amount) of each gene. In addition, the values of Cy3 ™ and Cy5 ™ signal strengths can be normalized using a variety of parameters. The image processing and reading process performed by the detection unit 250 are well known to those skilled in the art to which the present invention pertains, and thus detailed description thereof will be omitted. The biochip 200, which has been inspected by the detector 250, is transferred to the detachment point by the transfer unit 240 and then separated from the mounting unit 220.

The filter unit 260 transmits only a predetermined wavelength band from the light emitted from the fluorescent material of the target bio device on the biochip 200, wherein the wavelength band of the light filtered through the filter unit 260 is the emission of the fluorescent material. Means the wavelength band. The filter unit 260 is composed of a circular wheel-shaped filter wheel and a plurality of openings formed in the filter wheel. Each opening is provided with emission filters, and is formed to select desired filtering members while rotating about a central axis.

The focusing unit 270 adjusts the focus by moving the detector 250 in the vertical direction (ie, Z-axis direction). Focusing of the focusing unit 270 may be performed by detecting three or more reference points formed on the biochip 200. Alternatively, three or more samples on the biochip 200 may be detected. However, when focusing is performed by a sample on the biochip 200, there is a problem that accurate focusing is not easy due to the optical characteristics of each sample, so that a reference point is set in an area where no sample exists, and the set reference point is set. It is preferable to perform the focus control by detecting. At this time, the position of the reference point is set in advance. 4 illustrates a detailed configuration of the focusing unit 270.

Referring to FIG. 4, the focusing unit 270 includes a reference point detector 272, a profile analyzer 274, and a distance controller 276.

The reference point detector 272 detects an image of the reference points 202, 204, and 206 from the biochip 200 mounted on the mounting unit 220. To this end, the transfer unit 220 transfers the biochip 200 to a detection point, and then the detection unit 250 may acquire images of at least three reference points 202, 204, and 206 from the biochip 200. The biochip 200 is intermittently transferred from one end to the other end. The reference points 202, 204, and 206 are selected from at least three locations from regions where no sample is present on the biochip 200. In this case, the reference points 202, 204, and 206 may be displayed on the biochip 200. As such, a process of acquiring images of reference points 202, 204, and 206 from the biochip 200 may be referred to as a chip scanning process. The reference point detector 272 detects an image of the reference points 202, 204, and 206 through chip scanning. An image of the reference point detected by the reference point detector 272 is shown in FIG. 5. The detection operation of the reference point detector 272 may be performed by operation control of the transfer unit 220 and the detector 250.

The profile analyzer 274 analyzes an optical profile of an image corresponding to each reference point 202, 204, or 206 and calculates a height difference between each reference point 202, 204, and 206. At this time, the profile analyzer 274 detects the detection areas corresponding to the respective reference points 202, 204, and 206 (in the case of the profile shown in FIG. 5, (1932, 4142) to (1998, 4200) on the XY plane. That is, in the case where the vertex of the plane formed by the surface of the biochip is the origin, the height on the Z-axis (9600 to 16800 pixels in the case of the profile shown in FIG. 5) existing in the area represented by the pixel distance on the XY axis. Distance) is set as the height value of each reference point 202, 204, 206.

The distance controller 276 moves the detector 250 upwards or downwards by a distance corresponding to an average value of the height values of the respective reference points 202, 204, and 206 calculated by the profile analyzer 274. Adjust At this time, in order to prevent the frequent movement of the detection unit 250, the distance adjusting unit 276 is a height difference between each reference point (202, 204, 206) calculated by the profile analysis unit 274 has a predetermined allowable value. Only when exceeding, it is preferable to perform the focus setting process by the movement of the detector 250.

In the above description of the focus setting process, it is described that the profile analyzer 274 sets the height value of the height on the Z axis existing in the detection area corresponding to each reference point 202, 204, 206 as the height value. However, the maximum height on the Z-axis existing in the detection area corresponding to each reference point 202, 204, 206 may be set as the height value of the reference point 202, 204, 206. On the other hand, the height value on the Z axis existing in the detection area corresponding to each reference point 202, 204, 206 is determined by the intensity of light incident from the respective reference points 202, 204, 206 to the detection unit 250. Corresponds.

The controller 280 controls the overall operation of the biochip scanner. When the user mounts the biochip 200 on the mounting unit 220, the controller 280 outputs a control signal instructing the transfer unit 230 to transfer the mounting unit 220 from the mounting point to the detection point. Next, the controller 280 drives the light source unit 230, and instructs the focusing unit 270 to calculate data for chip scanning and distance control for focus adjustment. When the focus setting procedure by the focusing unit 270 is completed, the control unit 280 controls the detection unit 250 to perform a detection operation.

A process of analyzing the biochip 200 using the biochip scanner described with reference to FIGS. 2 and 3 will be described below.

When the biochip 200 is a DNA chip, hybridized cDNA prepared by reverse transcription reaction of DNA immobilized on the chip (single stranded DNA) and mRNA to be interpreted (A = T, C = G complementary coupling principle) Measuring the amount of mRNA is a DNA chip experiment, the enzyme reaction or the manipulation itself is the same as previously developed methods. However, when compared to the conventional manipulation used in hybridization, experiment with a very small amount (10 ~ 100 ㎕) reaction solution, and the amount of DNA immobilized on the DNA chip (10s pL), so the change in the distribution of DNA amount is large, correct this Data processing to do that is necessary.

In general, when experimenting with a DNA chip, in order to compare data between experiments, the RNA sample to be controlled and the two kinds of RNA samples to be investigated are labeled by reverse transcription with each fluorescent material. The fluorescent material used for DNA chip interpretation is dUTP, which is a combination of Cy3 ™ and Cy5 ™, and is labeled on the cDNA with almost the same efficiency. Since the fluorescent material has different absorption wavelengths and fluorescence wavelengths, the respective fluorescence intensities can be measured. As the light source 231, a He-Ne laser having an excitation wavelength such as 543 nm or 633 nm is used. Cy3 ™ has an absorption wavelength of 550 nm and a fluorescence wavelength of 570 nm. Cy5 ™ has an absorption wavelength of 649 nm and a fluorescence wavelength of 670 nm.

6 is a diagram illustrating a configuration of an embodiment of a multi-channel biochip scanner.

Referring to FIG. 6, the multi-channel biochip scanner includes a plurality of light sources 231 and 237 in the light source unit 230. Other components of the multi-channel biochip scanner illustrated in FIG. 6 are the same as corresponding components of the biochip scanner described with reference to FIGS. 2 and 3, and thus, detailed descriptions thereof will be omitted. However, in relation to the configuration of the light source unit 230, the multi-channel biochip scanner includes a plurality of light sources 231 and 237, and thus additionally requires a fourth reflection mirror 238 and a beam splitter 239. The fourth reflecting mirror 238 redirects the light emitted from the second light source 237 to the beam splitter 239. The beam splitter 239 changes the path of the incident light reflected by the fourth reflection mirror 238 to be directed to the first reflection mirror 232, and passes the light emitted from the first light source 231 to pass the first light. To the reflective mirror 232. By the operation of the beam splitter 239, the paths of the light emitted from the two light sources 231 and 237 are combined into one.

As described above, even if a plurality of light sources are configured to allow light to pass through one path, it is possible to reduce the size and cost of equipment. In addition, since the genetic information is detected from the biochip by two light sources 231 and 237 having different wavelengths, more accurate analysis is possible. In general, when experimenting with a DNA chip, in order to compare data between experiments, the RNA sample to be controlled and the two kinds of RNA samples to be investigated are labeled by reverse transcription with each fluorescent material. The fluorescent material used for DNA chip interpretation is dUTP, which is a combination of Cy3 ™ and Cy5 ™, and is labeled on the cDNA with almost the same efficiency. Since this fluorescent substance is different from an absorption wavelength and a fluorescence wavelength, each fluorescence intensity can be measured. He-Ne-based lasers having excitation wavelengths of 543 nm and 633 nm are used as the first and second laser beam sources 231 and 232, respectively. Cy3 ™ has an absorption wavelength of 550 nm and a fluorescence wavelength of 570 nm. Cy5 ™ has an absorption wavelength of 649 nm and a fluorescence wavelength of 670 nm.

7 is a block diagram showing a detailed configuration of a light compensation device that can be applied to a biochip scanner according to the present invention, Figure 8 is a view showing the configuration of an embodiment of a biochip scanner equipped with a light compensation device .

7 and 8, the light amount compensation unit 290 includes a light receiving unit 292, a compensation value calculating unit 294, and a compensation unit 296. The operation of the light amount compensation unit 290 is controlled by the controller 280. The light receiving unit 292 is installed to face the light source unit 230 to detect the light emitted from the light source unit 230 and reflected by the biochip 200. The compensation value calculating unit 294 compares the intensity of the light detected by the light receiving unit 292 with a preset reference intensity to calculate a difference value between the two. If the difference between the two is larger than a predetermined allowable value, the compensation value calculator 294 outputs a compensation signal corresponding to the difference between the two to the compensation unit 296. The compensator 296 adjusts the aperture of the detector 250 according to the input compensation signal to adjust the amount of light incident to the detector 250. The light compensation device may be separately provided from the autofocus control device and may be provided independently of the biochip scanner.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific preferred embodiments described above, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

According to the biochip scanner having a focus control function according to the present invention, since it is possible to automatically focus on each sample on a biochip having a different surface slope, it is possible to detect whether the gene is expressed more accurately. In addition, by implementing an autofocus control function in the biochip scanner, it is possible for the device operator to alleviate the inconvenience of adjusting the focal length. On the other hand, by mounting the light amount compensation device in the biochip scanner there is an advantage that the resolution of the sample image does not decrease even if the intensity of light emitted from the light source changes over time.

Claims (7)

A light source unit 230 for irradiating light to a detection point; A transfer unit 240 for transferring the biochip 200 so that the light is irradiated to two or more reference points spaced apart from each other on the biochip 200; A detector 250 positioned above the detection point and configured to detect light irradiated to each reference point and output an image corresponding to each reference point; And The distance corresponding to the average value of the intensity of light obtained from each image corresponding to each reference point received from the detector 250 is set as a focal length, and the detector 250 is based on the set focal length. And a focusing unit (270) for moving upwards or downwards to adjust a focus corresponding to the biochip (200). The method of claim 1, The focusing unit 270, The transfer unit 240 is controlled such that each reference point on the biochip 200 is located at the detection point, and sequentially detects light irradiated to each reference point located at the detection point to detect each of the reference points. A reference point detector 272 for controlling the detector 250 to output an image corresponding to the reference point; A profile analyzer 274 for calculating a height difference between the reference points from an image corresponding to each reference point; And And a distance adjuster 276 for adjusting the focus of the detector 250 by moving the detector 250 upwards or downwards by a distance corresponding to the average value of the height difference between the calculated reference points. Featured biochip scanner. The method of claim 2, The profile analyzer 274 sets the average value of the heights in the vertical direction of the pixel bar existing in the detection area of the image corresponding to each reference point as the height value of each reference point. Biochip scanner. The method of claim 2, The distance adjusting unit (276) is a biochip scanner, characterized in that to perform a fraud focal length adjustment process when the difference between the height value of each reference point exceeds a preset allowable value. The method of claim 1, The light source unit 230 includes two or more light sources 231 and 237 for generating light having different wavelengths. The light emitted from each of the light sources (231, 237) is irradiated through the same optical path to the detection point. The method according to claim 1 or 5, And a light amount compensator 290 installed to face the light source 230 to detect light reflected by the biochip 200 and output a light compensation value corresponding to the detected intensity of the reflected light. Biochip scanner, characterized in that. The method of claim 6, The light amount compensation unit 290, A light receiving unit 292 installed to face the light source unit 230 to detect light emitted from the light source unit 230 and reflected by the biochip 200; The difference value is calculated by comparing the intensity of the light detected by the light receiving unit 292 with a reference intensity set in advance, and when the calculated difference value is larger than a preset allowable value, the difference value corresponds to the calculated difference value. A compensation value calculation unit 294 for outputting a compensation signal to be performed; And And a compensator (296) for adjusting the amount of light incident on the detector (250) by adjusting the aperture of the detector (250) according to the compensation signal.

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