Imaging equipment is one of the most commonly used instruments in biological laboratories, providing an imaging basis directly for your paper. The quality of these images, sometimes even determines whether your paper can be published. Having a good, stable device is also the wish of the mentor and technical director. So, how to choose a good imaging device from a variety of markets? Are many of the devices known as "Ace" really able to score full marks? This article teaches you three important points to choose an imaging system:
Key point 1: Practice the truth, try to know
Every imaging equipment manufacturer has its own product, “Wang Po sells melons, sells and boastsâ€, and often gives you two hours of classes without rest, what “patent technologyâ€, “humanized designâ€, “life science industry award†". Only you can't think of it, there is nothing he can't do, but what do these things mean to the user? Not many people can tell it! Easy to use is the last word! Let me say that it is a big deal, let me try it, not everything is clear! Now most manufacturers provide Demo machine services, as well as technical staff to answer questions on the spot, then please play, really fight with the real gun, who has good performance, excellent price, then who I want!
Of course, our actual test results are only for our own samples and on-site demo machines. We cannot rely on this to judge too many brands and related models. Due to specific application limitations, differences in operational skills, and possible differences in instrument status, we may not give a fair evaluation. But in any case, these messages are very important to our buyers and users.
Point 2: Only select equipment that meets the requirements of your own laboratory. <br>The various imaging equipments of various brands and models on the market can be divided into two categories, namely, photo imaging and scanning imaging. Photographic imaging simply means that the relative position of the sample and the camera does not move, and can be performed in a single imaging or multiple imaging. In the scanning imaging, the camera locally images the sample, and then the entire sample is imaged by the movement of the sample or the camera. Photographic imaging is currently mainly used for CCD camera imaging, which can often be used to perform weak chemiluminescence and bioluminescence imaging because of the different exposure times. Scanning imaging is widely used in large samples and multi-channel imaging due to its high precision and repeatability. It can be said that for large sample or multi-channel applications, you can choose to scan and image, try not to choose photo imaging! The principle is clear, and the selection is simple! Different principles lead to the best choice for different applications, so don't trust anything like "Almighty King", no single machine can take all the application areas.
Here are some simple examples of the most common applications in the lab:
Protein electrophoresis gel: Generally such gels are dyed or silver stained and white light transmitted. For small gels, you can choose a general gel imaging device, but for large gels, especially two-dimensional gels, there are geometric distortions due to CCD photo imaging, and the lens effect can also cause signal intensity differences in different regions. CCD photography does not guarantee that the imaging parameters of different gels are consistent, so scanning imaging is the best choice.
Nucleic acid electrophoresis gel: Generally, such gels are EB-stained, UV-excited, and the gel is small. It is recommended to use a general gel imaging device.
Transfer film: General transfer film has different detection methods such as colorimetric colorimetry, isotope, chemiluminescence and fluorescence. Colorimetric coloring is the production of colored bands or spots, usually using ordinary gel imaging equipment; isotope can be exposed by pressure film, but time-consuming, laborious and easy to over-saturation, the more common method is Fujifilm's phosphor screen imaging technology, invented in 1981, allows the phosphor screen of the signal latent image to acquire the isotope signal by laser scanning. Chemiluminescence is currently the most commonly used detection method for Western blotting. Undoubtedly, cold CCD photo imaging is most suitable for this weak optical signal. Fluorescence is the most amazing and promising of all these detection methods! This is not only because of the widest dynamic range of fluorescent dyes, but also because it provides us with a multi-channel detection pathway. Of course, you can use a single fluorescence detection, and your requirements for gel imaging equipment include new laser sources and corresponding filters. If you are a perfectionist, or if you need to image adjacent or overlapping target molecules, multi-channel fluorescence detection is the best choice! At this time, scanning imaging is definitely the best choice, so the choice is not only because scanning imaging can bring higher sensitivity and resolution, but more importantly, there is no geometric distortion between different channels, and the fitting is good.
Microplates and other special requirements: For photo imaging, imaging of microplates becomes more complicated due to geometric distortions, and generally requires a dedicated calibration device. Of course, no additional attachment is required if scanning imaging is used. Many laboratories are now very interested in small animal imaging, but it is really not a simple matter for small animals. On the one hand, small animals need to be anesthetized and fixed; on the other hand, three-dimensional positioning of signal positions is required. Therefore, PET/CT, which provides both functional, metabolic, and anatomical images, is the most powerful tool for performing such imaging. Due to space limitations, this section will not introduce more.
Key point 3 Parameter details are important
When we can't distinguish the performance of the instrument after checking the demo of the instrument, in addition to the use and evaluation of the brother department, we can only open the instrument to see the parameters. Of course, there are tricks to see the parameters. Many of the parameters of the imager are written in dozens, but in fact, the most critical ones are just a few. When we compare the parameters of different manufacturers, we must pay attention to only the key, but the parameters that are irrelevant can be turned a blind eye! In addition, don't be deceived by the manufacturer's own rating of the corresponding product. His scoring system is only relative to his own product, even if he gives the highest score of "5" points, and other manufacturers' products. Compared to performance, it may still be garbage-level!
For scanning imaging, sensitivity is generally not a problem. The most important thing we should focus on is resolution. Of course, the resolution is as long as we can meet our requirements. For small gels, membranes and microplates, the general resolution is 25um. The left and right should be enough! After meeting the resolution, a more important parameter is in front of us, that is, the dynamic range. In short, the dynamic range determines whether you can see both strong and weak signals on a single glue at the same time. And they maintain a good quantitative relationship between them! The general dynamic range is expressed in orders of magnitude. The larger the number, the wider the dynamic range!
For laser scanning imaging systems, the situation is more complicated. There are many things to consider and compare from lasers and filters to beamsplitters and detectors. Also limited to the length, will be described in detail later.
The following mainly introduces the parameters of the most commonly used coherent imager in the laboratory. According to principle 1, if you mainly use it to shoot common nucleic acid glue or protein glue, then almost all the imagers on the market can meet your needs very well. In addition to the price factor, the comparison is Some irrelevant indicators such as "Is it easy to operate and stylish?" The real need for a deliberate investigation is the user who is ready to do chemiluminescence. They have high sensitivity requirements and also require a wide dynamic range.
To capture the faint chemiluminescence, you need a good CCD camera and lens. In general, the cooling temperature of a CCD camera is closely related to the background noise. The lower the temperature, the lower the noise. Therefore, the absolute cooling temperature of -25 ° C is the first requirement for the camera (lower temperature, noise reduction effect is not obvious, and quantum efficiency will be greatly affected); in addition, larger pixels can provide higher Light harvesting efficiency; so for the same size of CCD chip, you need to pay attention to the size of the pixel. The parameters of the lens are simple. Since we only need to observe close-range samples and generally adjust the sample position (some manufacturers even provide electric sample lifting platforms), there is basically no need to choose long lenses or zoom lenses; however, because we need to detect weak The chemiluminescence, the aperture of the lens is very important, generally the smaller the F value, the greater the amount of light passing through, and the inverse square relationship, so we generally need to choose the lens with the smallest aperture F value. In addition, if the lens is electric, we can save the trouble of opening the case and repeatedly adjusting the aperture and focus manually.
Other things we need to consider include light sources, filters, and black boxes. The type of light source and the uniformity of illumination, the number of filters and the shading effect of the black box are all within our consideration. Of course, if the imager's CCD and lens configuration are good, generally these components will not be too bad.
Key point 1: Practice the truth, try to know
Every imaging equipment manufacturer has its own product, “Wang Po sells melons, sells and boastsâ€, and often gives you two hours of classes without rest, what “patent technologyâ€, “humanized designâ€, “life science industry award†". Only you can't think of it, there is nothing he can't do, but what do these things mean to the user? Not many people can tell it! Easy to use is the last word! Let me say that it is a big deal, let me try it, not everything is clear! Now most manufacturers provide Demo machine services, as well as technical staff to answer questions on the spot, then please play, really fight with the real gun, who has good performance, excellent price, then who I want!
Of course, our actual test results are only for our own samples and on-site demo machines. We cannot rely on this to judge too many brands and related models. Due to specific application limitations, differences in operational skills, and possible differences in instrument status, we may not give a fair evaluation. But in any case, these messages are very important to our buyers and users.
Point 2: Only select equipment that meets the requirements of your own laboratory. <br>The various imaging equipments of various brands and models on the market can be divided into two categories, namely, photo imaging and scanning imaging. Photographic imaging simply means that the relative position of the sample and the camera does not move, and can be performed in a single imaging or multiple imaging. In the scanning imaging, the camera locally images the sample, and then the entire sample is imaged by the movement of the sample or the camera. Photographic imaging is currently mainly used for CCD camera imaging, which can often be used to perform weak chemiluminescence and bioluminescence imaging because of the different exposure times. Scanning imaging is widely used in large samples and multi-channel imaging due to its high precision and repeatability. It can be said that for large sample or multi-channel applications, you can choose to scan and image, try not to choose photo imaging! The principle is clear, and the selection is simple! Different principles lead to the best choice for different applications, so don't trust anything like "Almighty King", no single machine can take all the application areas.
Here are some simple examples of the most common applications in the lab:
Protein electrophoresis gel: Generally such gels are dyed or silver stained and white light transmitted. For small gels, you can choose a general gel imaging device, but for large gels, especially two-dimensional gels, there are geometric distortions due to CCD photo imaging, and the lens effect can also cause signal intensity differences in different regions. CCD photography does not guarantee that the imaging parameters of different gels are consistent, so scanning imaging is the best choice.
Nucleic acid electrophoresis gel: Generally, such gels are EB-stained, UV-excited, and the gel is small. It is recommended to use a general gel imaging device.
Transfer film: General transfer film has different detection methods such as colorimetric colorimetry, isotope, chemiluminescence and fluorescence. Colorimetric coloring is the production of colored bands or spots, usually using ordinary gel imaging equipment; isotope can be exposed by pressure film, but time-consuming, laborious and easy to over-saturation, the more common method is Fujifilm's phosphor screen imaging technology, invented in 1981, allows the phosphor screen of the signal latent image to acquire the isotope signal by laser scanning. Chemiluminescence is currently the most commonly used detection method for Western blotting. Undoubtedly, cold CCD photo imaging is most suitable for this weak optical signal. Fluorescence is the most amazing and promising of all these detection methods! This is not only because of the widest dynamic range of fluorescent dyes, but also because it provides us with a multi-channel detection pathway. Of course, you can use a single fluorescence detection, and your requirements for gel imaging equipment include new laser sources and corresponding filters. If you are a perfectionist, or if you need to image adjacent or overlapping target molecules, multi-channel fluorescence detection is the best choice! At this time, scanning imaging is definitely the best choice, so the choice is not only because scanning imaging can bring higher sensitivity and resolution, but more importantly, there is no geometric distortion between different channels, and the fitting is good.
Microplates and other special requirements: For photo imaging, imaging of microplates becomes more complicated due to geometric distortions, and generally requires a dedicated calibration device. Of course, no additional attachment is required if scanning imaging is used. Many laboratories are now very interested in small animal imaging, but it is really not a simple matter for small animals. On the one hand, small animals need to be anesthetized and fixed; on the other hand, three-dimensional positioning of signal positions is required. Therefore, PET/CT, which provides both functional, metabolic, and anatomical images, is the most powerful tool for performing such imaging. Due to space limitations, this section will not introduce more.
Key point 3 Parameter details are important
When we can't distinguish the performance of the instrument after checking the demo of the instrument, in addition to the use and evaluation of the brother department, we can only open the instrument to see the parameters. Of course, there are tricks to see the parameters. Many of the parameters of the imager are written in dozens, but in fact, the most critical ones are just a few. When we compare the parameters of different manufacturers, we must pay attention to only the key, but the parameters that are irrelevant can be turned a blind eye! In addition, don't be deceived by the manufacturer's own rating of the corresponding product. His scoring system is only relative to his own product, even if he gives the highest score of "5" points, and other manufacturers' products. Compared to performance, it may still be garbage-level!
For scanning imaging, sensitivity is generally not a problem. The most important thing we should focus on is resolution. Of course, the resolution is as long as we can meet our requirements. For small gels, membranes and microplates, the general resolution is 25um. The left and right should be enough! After meeting the resolution, a more important parameter is in front of us, that is, the dynamic range. In short, the dynamic range determines whether you can see both strong and weak signals on a single glue at the same time. And they maintain a good quantitative relationship between them! The general dynamic range is expressed in orders of magnitude. The larger the number, the wider the dynamic range!
For laser scanning imaging systems, the situation is more complicated. There are many things to consider and compare from lasers and filters to beamsplitters and detectors. Also limited to the length, will be described in detail later.
The following mainly introduces the parameters of the most commonly used coherent imager in the laboratory. According to principle 1, if you mainly use it to shoot common nucleic acid glue or protein glue, then almost all the imagers on the market can meet your needs very well. In addition to the price factor, the comparison is Some irrelevant indicators such as "Is it easy to operate and stylish?" The real need for a deliberate investigation is the user who is ready to do chemiluminescence. They have high sensitivity requirements and also require a wide dynamic range.
To capture the faint chemiluminescence, you need a good CCD camera and lens. In general, the cooling temperature of a CCD camera is closely related to the background noise. The lower the temperature, the lower the noise. Therefore, the absolute cooling temperature of -25 ° C is the first requirement for the camera (lower temperature, noise reduction effect is not obvious, and quantum efficiency will be greatly affected); in addition, larger pixels can provide higher Light harvesting efficiency; so for the same size of CCD chip, you need to pay attention to the size of the pixel. The parameters of the lens are simple. Since we only need to observe close-range samples and generally adjust the sample position (some manufacturers even provide electric sample lifting platforms), there is basically no need to choose long lenses or zoom lenses; however, because we need to detect weak The chemiluminescence, the aperture of the lens is very important, generally the smaller the F value, the greater the amount of light passing through, and the inverse square relationship, so we generally need to choose the lens with the smallest aperture F value. In addition, if the lens is electric, we can save the trouble of opening the case and repeatedly adjusting the aperture and focus manually.
Other things we need to consider include light sources, filters, and black boxes. The type of light source and the uniformity of illumination, the number of filters and the shading effect of the black box are all within our consideration. Of course, if the imager's CCD and lens configuration are good, generally these components will not be too bad.
Many people always love to use mocking tone to say other people: "You have neuropathy." in real life, It is essentially different with medical psychosis. First of all, it is clear that mental illness is a mental incapacity, behavioral abnormalities as the main features of the disease, regardless of any approach, mental patients have no civil capacity, but also can not be founding, more and more studies show that psychosis is from the pre-born which is a neurological disease caused by a genetic factor (gene) that has changed. The treatment of psychosis mainly take drug, behavioral therapy, work therapy, recreational therapy, psychological treatment and other aspects of grooming to eliminate or reduce the various obstacles to the patient. In addition, diet therapy is also a very good choice.In recent years, anti-psychotropic drugs continue to make a breakthrough, a variety of new drugs emerge in an endless stream, to bring more treatment of mental illness.
Anti-Psychotics Intermediate, Psychotisc Drugs,Anti Psychotics,Antipsychotics for Anxiety and Depression,Amisulpride Intermediate
Taizhou Volsen Chemical Co., Ltd. , https://www.volsenchem.com