Fluorescent microscope from a mobile phone
A group of researchers from the University of California developed a mobile phone-based device for photographing DNA fragments, as well as an application for calculating the length of these fragments. An article on the invention, recently appeared on the website of the magazine ASC Nano .
Signature to the picture: the appearance of the device with the launched mobile application, the scheme of its internal structure and photographs of DNA fragments: on the left — obtained using the proposed device, on the right — using a fluorescent microscope. The scale is 10 micrometers.
The design of the device is relatively simple: a mobile phone with a built-in camera (the Lumia 1020 smartphone was used in this work) was equipped with an additional magnifying lens, removed from another phone, and a laser with a wavelength of 450 nm. A laser was needed to excite the fluorescence of the dye, which was labeled with the DNA fragments under investigation. The sample was placed between two glass beads and illuminated with a laser, while the dye emitted light, which was fixed by the camera of the phone. Additional light filters installed between the two lenses, passed only the glow of the dye and delayed any other non-specific signal. A total of 10-15 photographs of the sample were taken, each with an exposure of about 4 seconds. The obtained data were processed using a special algorithm that allows to calculate the length of DNA fragments that fell into the frame. It is assumed that these calculations will be made not on the phone, but on a special server: the mobile application will send images for processing and return the results already ready to the user.
The total weight of the device is about 190 grams, including three AAA batteries for powering the laser, and its value, according to the authors of the article, does not exceed 400 euros. At the same time, photographs obtained with the help of such a simple device are inferior in quality to images taken with a conventional fluorescent microscope, but they do allow covering a larger shooting area of about 2 mm2. At the same time, it is possible to obtain images of DNA fragments with a size of 10 kilobases and above (1 kilobase = 1000 base pairs), and the developed software allows achieving acceptable accuracy in measuring the length of fragments (the average error is less than 1 kilobase), and the measurement accuracy increases with fragment lengths.
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The authors of the work believe that their invention can be extremely useful for the rapid diagnosis of oncological or neurological diseases associated with changes in the length of individual sections of the genome. In addition, the authors hope that their work will encourage other researchers to search for non-standard ways of using modern mobile technology - smartphones and tablet computers.
Signature to the picture: the appearance of the device with the launched mobile application, the scheme of its internal structure and photographs of DNA fragments: on the left — obtained using the proposed device, on the right — using a fluorescent microscope. The scale is 10 micrometers.
The design of the device is relatively simple: a mobile phone with a built-in camera (the Lumia 1020 smartphone was used in this work) was equipped with an additional magnifying lens, removed from another phone, and a laser with a wavelength of 450 nm. A laser was needed to excite the fluorescence of the dye, which was labeled with the DNA fragments under investigation. The sample was placed between two glass beads and illuminated with a laser, while the dye emitted light, which was fixed by the camera of the phone. Additional light filters installed between the two lenses, passed only the glow of the dye and delayed any other non-specific signal. A total of 10-15 photographs of the sample were taken, each with an exposure of about 4 seconds. The obtained data were processed using a special algorithm that allows to calculate the length of DNA fragments that fell into the frame. It is assumed that these calculations will be made not on the phone, but on a special server: the mobile application will send images for processing and return the results already ready to the user.
The total weight of the device is about 190 grams, including three AAA batteries for powering the laser, and its value, according to the authors of the article, does not exceed 400 euros. At the same time, photographs obtained with the help of such a simple device are inferior in quality to images taken with a conventional fluorescent microscope, but they do allow covering a larger shooting area of about 2 mm2. At the same time, it is possible to obtain images of DNA fragments with a size of 10 kilobases and above (1 kilobase = 1000 base pairs), and the developed software allows achieving acceptable accuracy in measuring the length of fragments (the average error is less than 1 kilobase), and the measurement accuracy increases with fragment lengths.
')
The authors of the work believe that their invention can be extremely useful for the rapid diagnosis of oncological or neurological diseases associated with changes in the length of individual sections of the genome. In addition, the authors hope that their work will encourage other researchers to search for non-standard ways of using modern mobile technology - smartphones and tablet computers.
Source: https://habr.com/ru/post/375133/
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