Biochip reader with enhanced illumination and bioarray positioning apparatus
A method of illumination and illumination apparatus are provided in a biochip reader. Illumination is provided by a non-collimated laser source or a light emitting diode (LED). The light is directed to opposing sides of a glass substrate by a pair of optical fiber bundles. The glass substrate carries a bioarray. Each of the optical fiber bundles are splayed out to make a fan, the fan being one fiber thick and defining a line of optical fiber faces. This process randomizes any non-uniformity in the illumination source, creating a more uniform illumination source. A respective divergent diffuser engages each row of optical fiber faces coupling and diffusing light substantially evenly through the opposing sides of the glass substrate to illuminate the bioarray supported by the glass substrate. The glass substrate functions as a secondary light guide. The divergent diffusers separate the optical fiber faces from the edges of the glass substrate, protecting the optical fibers from mechanical damage. A glass holder supports the glass substrate carrying the bioarray. The glass holder including a plastics springs member in spring contact engagement with the glass substrate for positioning said bioarray in a focal plane. Light also can be directed to opposing ends of the glass substrate by a second pair of optical fiber bundles. Also a single optical fiber bundle can be used to direct light in one side of the glass substrate or three optical fiber bundles can be used to direct light into the glass substrate. This method of illumination provides a superior signal to noise ratio as compared with conventional illumination systems.
1. A biochip reader comprising:
an illumination source,
a glass substrate carrying a bioarray;
an optical fiber bundle directing said light from said illumination source to one side of said glass substrate; said optical fiber bundle including a plurality of optical fibers;
a reflector positioned proximate to another side of said glass substrate spaced apart from said fiber optic fan; said reflector for reflecting outgoing light back into said glass substrate
an optical system;
a glass holder supporting and aligning said glass substrate carrying the bioarray with said optical system, and
said glass holder including a plastic springs member in contact engagement with said glass substrate with low contact forces for positioning said bioarray in a focal plane of said optical system.
2. A biochip reader as recited in claim 1 includes a positioner coupled to said glass holder for positioning said bioarray within a field of view of said optical system.
3. A biochip reader as recited in claim 1 includes an optical fiber fan formed by said optical fiber bundle proximate to a side of said glass substrate carrying said bioarray, said optical fiber fan defining a line of optical fiber faces of said plurality of optical fibers.
4. A biochip reader as recited in claim 3 includes a divergent diffuser separating said optical fiber faces from an edge of said glass substrate, said divergent diffuser protecting said optical fibers from mechanical damage.
5. A biochip reader as recited in claim 1 wherein said plastic springs member is formed of a pressure sensitive fastener material.