Introduction of main light sources in gel imaging system
The introduction of the main light source in the gel imaging system, the gel imaging system, as the name suggests, uses a set of optical systems that can be used to imaging the gel. The light source is an important part of its optical path system. It can be said that without the light source, the imaging system can hardly be used. However, compared with CCD, lens and analysis software, it often fails to get the attention it deserves. We often encounter such users. They know that when the system light source fails or the whole system is scrapped, we do not know that there are two kinds of ultraviolet lamps, 305nm or 365nm, in gel imaging transmission ultraviolet, or we can not understand the difference between them. Customer service is not in place, but it also reflects our lack of attention and lack of understanding of the source of gel imaging system. We write this article to help users clarify their differences and their respective roles, so that you can better choose, purchase, use and maintain gel imaging systems.
Next, we introduce the various sources and their uses of the gel imaging system. First of all, it is a white light source with double reflector. It is also used by many light sources. It is usually used as the lighting source of the system, that is, to place or adjust the position of DNA glue or protein glue, or to adjust the focus when the lens is used. Of course, the reflective white light should also be turned on when imaging non transparent fibrin glue or other imaging materials.
Secondly, transmitted white light, commonly known as white light plate, is mainly used for protein glue shooting. Because the white light plate is located above the transmitted ultraviolet light box, in order not to affect the use of transmitted ultraviolet light source, but also to save indoor space, the white light plate can be folded and erected at the back of the box.
The transmission ultraviolet light source, that is, the ultraviolet transmission light box, is mainly used for DNA glue shooting. As the commonly used fluorescent dye of DNA is EB (Ethidium bromide), and the standard 302nm ultraviolet transmittance instrument is used to excite and emit the orange red signal, it can be photographed with the gel imaging system with CCD imaging head, so the ultraviolet transmission wavelength is usually 305nm segment.
The main reason is that it is not widely used. It is only used in the imaging of non transparent DNA gel carrier such as paper chromatography. The commonly used transparent agarose gel and polyacrylamide gel are completely satisfied with the transmission light source, so most manufacturers only choose the ultraviolet reflection light source as the matching, but only the position and interface are reserved on the instrument.
It is also necessary to point out that the use of pull tray is due to chemiluminescence imaging without any light source. It is self luminous imaging. However, because the signal of chemiluminescence is weak and unstable, and the lens of the top chemiluminescent imaging system is often manually focused, a highly adjustable tray is needed for chemiluminescence imaging.
In addition, the three color LED light source mentioned above is three high light intensity reflection exciters (475 nm, 534 nm, 632 nm), which is an indispensable part of the multi-color fluorescence imaging system. Optical fiber interface of continuous wavelength light source is reserved in the dark box to expand to continuous wavelength light source (excitation wavelength range: 400-750nm) in the future. It covers some fluorescence requiring special excitation, and is mostly used for multi-color fluorescence (Cy3 / Cy5) and in vivo imaging.