Figure 3.

A high-density array of xylene cyanol FF spots. (A) An array of >2500 spots was produced in a 3.2 × 3.2-mm square by a single pen. It has a density of 25,000 spots/cm². Bar, 250 μm. (B) An array with alternating rows of water and concentrated dye solution was printed to test carryover. With careful pen cleaning, observed carryover is negligible. The white circles superimposed onto the image are 30 μm in diameter, and are spaced 180 and 90 μm apart in the horizontal and vertical directions, respectively.