Figure 7.

Example of parallel, multicolor fluorescence detection in 32 channels. (a) Image without an emission filter and a prism added in the optical pathway. The blue, green, and red signals from the ball lens array overlap on the image plane. (b) An emission filter is added to remove the blue excitation light from the laser. An array of yellow dots is observed since the green and red fluorescence signals from the same ball lens overlap. (c) A prism is added to split images of different colors on the detection plane. (d) An emission filter and a prism are added. Green and red fluorescence signals from 32 channels are simultaneously picked up. (e) Comparison of the signal to noise ratio improvement without and with a microball lens array. An 18 times improvement has been achieved with microball lenses.