<p>(A) Southern blot analysis. A part of <i>Amp</i><sup>r</sup> gene (0.7-kb) was amplified by PCR and used as the probe. (B) Primers designed for the insertion analysis of the target gene in A2-2 (<i>celA</i>) and D1-B1 (<i>celC</i>), and the theoretical results of PCR using the designed primers.</p