Example of nonradioactive hybridization (DIG labeled) of a PAC filter containing 27,648 clones with riboprobe 54E24-SP6. Filter is bar-coded (at left). Image was captured by a CCD camera and analyzed with the Xdigitize program. A grid was automatically superimposed on the filter, that is, 48 × 48 squares placed around guide dots (black ink spotted on the filter). Each of the squares contains 12 different clones, spotted in duplicate around the central guide dot, according to the pattern shown in the Classification’s window. Each pair of numbers represents a clone pair (guide dot is noted by −9). Levels of relative intensities are indicated as follows: 3 = high, 2 = medium, and 1 = faint. Two positive clones were scored on this filter; the arrow indicates clone 228A2.
