Patterned and switchable surfaces for biomaterial applications

Chapter 1 - Introduction(A)(B)(C)(D)(E)(F)Figure 1.6. DNA checkerboarding on 100 test site microelectronic array. In thisexperiment, all the microelectrodes on an agarose permlayer-coated 100 testsite chip are biased positive or negative in a checkerboard pattern, with thepolarity being reversed every 7 s. White light and fluorescent images areacquired in real-time using a charge coupled detector (CCD) camera anddigital tape recorder. (A) 100 test site chip under white light and the 100 testsite array with its 80 m diameter microlocations. (B) Fluorescent image ofthe rapid accumulation of fluorescent probe at the positively (+) biasedmicrolocation (white spots), and repulsion of the DNA probes from thenegatively biased microlocation (black spots). Note that the fluorescent DNAover the unactivated counter-electrodes on the perimeter of the device is notinfluenced during the checkerboard experiment. (C) Fluorescent DNA inrapid transport as the polarity is reversed after 7 s. (D) Fluorescent probesnow accumulating on the newly biased negative microlocations. (E)Transport after polarity reversal. (F) Accumulation of the fluorescent probeson the newly biased positive microlocations. From [92].1-34