Figure 1

Experimental flow. The procedure can be performed with either a single colony from a cDNA library at a time (single clone analysis, SCA) or several colonies in parallel (96 in mixed analysis, MA). After splitting up the plasmid preparation into 6 aliquots, two at a time are labeled at a Bgl I site with one of the fluorescent dyes FAM (blue), JOE (green), or NED (yellow) – step 1. Subsequently, the 6 fractions are digested individually employing 6 different restriction enzymes recognizing sites of 4 base pairs – step 2. 3 digests are mixed together and resolved on a gel in the presence of an internal size marker labelled with the dye ROX (red) – step 3. For the digital analysis, the existence of patterns derived from a SCA is probed in the MA. In the example given, the fingerprint is identified in lanes 1,3, and 6, thus 3 out of the 6 time 96 colonies analyzed contained the cDNA of the specific gene.