Patent Application
20130146786
The present invention relates to an apparatus for generating light, particularly to an apparatus for generating fluorescence.
In examination of genetics, molecular biology and animal/plant quarantine, a trace nucleic acid sample is fast amplified to a detectable amount via a nucleic acid amplification method, such as PCR (Polymerase Chain Reaction). The target nucleic acid of the reaction product is combined with a nucleic acid probe carrying a fluorescent material, a radioactive material or a coloring enzyme via a hybridization reaction, whereby the target nucleic acid can present fluorescence, radioactive images, or colors. The fluorescent reagent is 103 to 5×105 times more sensitive than the conventional coloring reagent. Therefore, many current biochips adopt fluorescent reagents to label the target materials.
Fluorescent images are observed, detected, analyzed, and captured with fluorescence microscopy, fluorometry, flow cytometry and photography. A specified fluorescent reagent needs an exciting light source having a specified range of wavelength. Therefore, the abovementioned technologies all involve adopting an exciting light source. When illuminated with an appropriate wavelength of light, a fluorescent material is exited to a high energy level. Then, the excited fluorescent molecule returns to a low energy level within a very short interval of time (10−8-10−4 sec) and releases the redundant energy in form of light. Therefore, a specified fluorescent reagent needs a matching exciting light source to achieve the best performance.
The exciting light sources include ultraviolet rays or laser beams. However, ultraviolet ray is likely to scatter and hard to transmit and penetrate. Thus, the ultraviolet-based test devices have to adopt special optical elements to enhance the sensitivity to ultraviolet rays. Therefore, the ultraviolet-based test devices are high-priced and economically inefficient. The laser beam is monochromatic, penetrative and easy to detect. However, the laser-based test devices need filters and splitters, which makes them bulky and hard to install.
Therefore, the conventional technique discloses a LED (Light Emitting Diode) module whose light intensity and combination of light colors can be adjusted, wherein the combination of the light colors is adjusted to obtain the wavelengths of lights able to excite the fluorescent reagent. However, only a specified wavelength of exciting light can attain higher exciting efficiency. Further, the wavelength range of the LED module may overlap the wavelength range of the excited fluorescent reagent. It is hard to determine whether the detected light intensity comes from purely the excited fluorescence or from both the excited fluorescence and the exciting light. Thus, the laser-based test devices may have poorer precision.
The primary objective of the present invention is to provide an exiting light source having a specified wavelength range to effectively excite fluorescence.
Another objective of the present invention is to solve the fluorescence detection problem caused by the fact that the wavelength range of the exciting light source is likely to overlap the wavelength range of the excited fluorescence.
To achieve the abovementioned objectives, the present invention proposes an apparatus for generating fluorescence, which comprises a blue LED emitting a light beam, a filter and a fluorescent material. The filter is arranged in front of the light beam emitted by the blue LED, receives the light beam and converts the light beam into a filtered light beam having wavelengths of 465-505 nm. The fluorescent material is arranged in one side of the filter and opposite to the blue LED and excited by the filtered light beam to emit fluorescence.
The present invention has the following characteristics:
2. The wavelength range of the filtered light beam can be adjusted to prevent from measurement errors caused by coincidence or overlap of the wavelength ranges of the filtered light beam and the excited fluorescence.
The technical contents of the present invention are described in detail in cooperation with drawings below.
Refer to
Refer to
The fluorescent material 30 could be 6-FAM, 5-FAM, Oregon Green-488, Alexa-488, Calcein, Cyanine-2, FAM, FITC (fluorescein isothiocyanat), FluorX, GFP, rsGFP, Oregon Green-500, Rhodamine 110, Rhodamine green, or SYBR green. The filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 492 nm for exciting the fluorescent material 30 of 6-FAM to emit fluorescence 31 having a wavelength of 517 nm, whereby the fluorescence exciting has the best efficiency. When the fluorescent material 30 is 5-FAM, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 494 nm to excite fluorescence 31 having a wavelength of 518 nm. When the fluorescent material 30 is Oregon Green-488, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 496 nm to excite fluorescence 31 having a wavelength of 524 nm. When the fluorescent material 30 is Alexa-488, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 495 nm to excite fluorescence 31 having a wavelength of 520 nm. When the fluorescent material 30 is Calcein, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 494 mn to excite fluorescence 31 having a wavelength of 517 nm. When the fluorescent material 30 is Cyanine-2, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 489 nm to excite fluorescence 31 having a wavelength of 506 nm. When the fluorescent material 30 is FAM, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 488 nm to excite fluorescence 31 having a wavelength of 508 nm. When the fluorescent material 30 is FITC, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 494 nm to excite fluorescence 31 having a wavelength of 518 mn. When the fluorescent material 30 is FluorX, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 494 nm to excite fluorescence 31 having a wavelength of 519 nm. When the fluorescent material 30 is GFP, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 488 nm to excite fluorescence 31 having a wavelength of 558 nm. When the fluorescent material 30 is rsGFP, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 488 nm to excite fluorescence 31 having a wavelength of 507 nm. When the fluorescent material 30 is Oregon Green-500, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 503 nm to excite fluorescence 31 having a wavelength of 522 nm. When the fluorescent material 30 is Rhodamine 110, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 496 nm to excite fluorescence 31 having a wavelength of 520 nm. When the fluorescent material 30 is Rhodamine green, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 502 nm to excite fluorescence 31 having a wavelength of 527 nm. When the fluorescent material 30 is
SYBR green, the filter 20 is adjusted to emit a filtered light beam 21 having a wavelength of 497 nm to excite fluorescence 31 having a wavelength of 520 nm.
In the present invention, the filter 20 is adjusted to emit a filtered light beam 21 having a specified wavelength range able to achieve the best fluorescence exciting efficiency. The filter 20 controls the intensity of the filtered light beam 21 to be distributed within the range of the nominal wavelength thereof ±15 nm, and the intensity of the filtered light beam 21 approaches zero outside the abovementioned range. Further, the nominal wavelength of the fluorescence 31 of the fluorescent material 30 excited by the filtered light beam 21 is far away from the nominal wavelength of the filtered light beam 21 by at least 15 nm. Therefore, the wavelength range of the fluorescence 31 would not overlap the wavelength range of the filtered light beam 21. Thus, the detection would not be affected by the overlap of wavelength ranges.
In conclusion, the present invention uses only a blue LED 10 to excite the fluorescence 31 and uses a filter 20 to control the wavelength and spectral range of the filtered light beam 21 to achieve the best fluorescence exciting efficiency. Further, the present invention also uses the filter 20 to prevent from the overlap of the wavelength ranges of the filtered light beam 21 and the fluorescence 31. Thus, the detection module 40 is exempted from being affected by overlap of wavelength ranges in measuring the intensity of the fluorescence 31.
