Fluorometer with low heat-generating light source
This invention concerns a fluorometer preferably combined with a thermal cycler useful in biochemical protocols such as polymerase chain reaction (PCR) and DNA melting curve analysis. The present flourometer features a low heat-generating light source such as a light emitting diode (LED), having a one-to-one correspondence to each of a plurality of sample containers, such as capped PCR tubes in a standard titer tray. The flourometer of the present invention further comprises an optical path between each LED and its correspondingly positioned container, and another optical path between each flourescing sample within the positioned container and an optical signal sensing means. The instrument can be computer controlled.
1. A combined fluorometer and thermal cycler, comprising:
a plurality of low heat-generating light sources;
a plurality of containers having caps;
means for positioning said plurality of containers into optical communication with said plurality of light sources, wherein each of said light sources communicates with one of said containers;
a thermally controlled base in close contact with said plurality of containers and a thermally controlled cover having a plurality of apertures, wherein each of said apertures corresponds with one of said containers and expands outward from said cap of said corresponding container;
a first optical path means for guiding light from said plurality of light sources to said plurality of containers;
an optical signal sensing means in optical communication with said plurality of containers;
a second optical path means for guiding emitted light from any sample in said plurality of containers to said optical signal sensing means; and
programmable control means for controlling the temperature of said plurality of containers according to a selected protocol.
2. The combined fluorometer and thermal cycler of claim 1 , wherein each of said apertures expands outwardly toward said optical signal sensing means at an included angle of about 10 degrees.
3. The combined fluorometer and thermal cycler of claim 1 , wherein each of said apertures is formed as a parabolic reflector.
4. The combined fluorometer and thermal cycler of claim 1 , wherein said plurality of containers is integrally formed within said means for positioning.
5. The combined fluorometer and thermal cycler of claim 1 , wherein at least one of said plurality of containers contains a potentially fluorescing sample.
6. The combined fluorometer and thermal cycler of claim 1 , wherein at least one of said plurality of containers contains reagents for polymerase chain reaction amplification.