Fabrication of Inverted High-Density DNA Microarrays in a Hydrogel.

Current techniques for making high-resolution, photolithographic DNA microarrays suffer from the limitation that the 3' end of each sequence is anchored to a hard substrate and hence is unavailable for many potential enzymatic reactions. Here, we demonstrate a technique that inverts the entire microarray into a hydrogel. This method preserves the spatial fidelity of the original pattern while simultaneously removing incorrectly synthesized oligomers that are inherent to all other microarray fabrication strategies.

Use of a Pteridine Moiety to Track DNA Uptake in Cells.

Fluorescence labeled oligonucleotides have a long history of being used to monitor nucleic acid transport and uptake. However, it is not known if the fluorescent moiety itself physically limits the number of pathways that can be used by the cell due to steric, hydrophobic, or other chemical characteristics. Here, we report a method for comparing the uptake kinetics of oligonucleotides labeled either with the fluorescent pteridine, 3-methyl-8-(2-deoxy-β-D-ribofuranosyl) isoxanthopterin (3MI), or the common fluorophore 5-carboxyfluorescein (5-FAM).

Wicking: a rapid method for manually inserting ion channels into planar lipid bilayers.

The planar lipid bilayer technique has a distinguished history in electrophysiology but is arguably the most technically difficult and time-consuming method in the field. Behind this is a lack of experimental consistency between laboratories, the challenges associated with painting unilamellar bilayers, and the reconstitution of ion channels into them. While there has be a trend towards automation of this technique, there remain many instances where manual bilayer formation and subsequent membrane protein insertion is both required and advantageous.