Microchip electrophoretic separations of neurotransmitters in under 100 s exemplify the good resolution and attomole detection sensitivity of these devices.

As low as 0.5 attomoles purified aequorin gave a signal-to-noise ratio of 1.8.

Excellent linearity was observed 0.99227-0.99999 and limit of detection values ranged from 63.75 attomoles to 1.21 femtomoles.

Microarray signal dynamic range was found to be linear across three orders of magnitude from 4.88 to 5000 attomoles.

Modifications were detected at concentrations four orders of magnitude lower than the corresponding parental nucleosides, and as low as 23.01 femtograms, 64.09 attomoles.

Complementary chi(3) charge screening studies indicate that the signal originates from 5 x 10(11) strands per square centimeter, or 6 attomoles of surface-bound oligonucleotides.