A scalable and modular lab-on-a-chip genetic analysis instrument.

We demonstrate a new and extremely inexpensive, multipurpose desktop system for operating lab-on-a-chip (LOC) devices. The system provides all of the infrastructure necessary for genetic amplification and analysis, with orders of magnitude improvement in performance over our previous work. A modular design enables high levels of integration while allowing scalability to lower cost and smaller size. The component cost of this system is ca. $600, yet it could support many diagnostic applications. We demonstrate an implementation of genetic amplification via polymerase chain reaction (PCR), and analysis using capillary electrophoresis (CE). The PCR is able to amplify from single or several copies of target DNA and the CE performance (e.g. sensitivity) is comparable to that of commercial photomultiplier-based confocal lab-on-chip instrumentation. We believe this demonstrates that the cost of infrastructure need no longer be a barrier to the wide-spread application of LOC technologies in healthcare and beyond.

Identification of the eye-brain-hand system with point processes: a new approach to simple reaction time.

By presenting a Poisson process of flashes to observers who hit a button as quickly as possible after each, the authors identified the system involved in simple reaction time (RT). The nonlinear kernels up to 2nd order were measured from the stimulus and response point processes. The 1st-order kernel is analogous to a histogram of simple RTs. The 2nd-order kernel shows complex patterns of nonlinear suppression and facilitation between pairs of flashes. Simple RT measured as the lag of the 1st-order kernel's peak agrees with RT from conventional discrete trial experiments. RTs are shorter and less variable when the flashes are separated by uniform rather than exponential delays, which shows that observers use the stimulus hazard function to become prepared to detect and respond to the flash.