Agarose gel electrophoresis of PCR products generated by IVb clonogrouping multiplex PCR (A), IIb clonogrouping multiplex PCR (B), and IIaIIc clonogrouping multiplex PCR (C). Lanes 2 to 12, L. monocytogenes strains of CC1 (CLIP2013/00068), CC2 (CLIP2012/00799), CC4 (CLIP2011/00181), CC6 (CLIP2010/01520), CC5 (CLIP2011/00140), CC3 (CLIP2011/00787), CC121 (CLIP2012/00189), CC155 (2010/01410), CC7 (CLIP2012/01275), CC8 (CLIP2012/01049), and CC9 (CLIP2010/01314), respectively; lane 13, negative control; lane 1, Smart Ladder small fragment (Eurogentec). Genes corresponding to the amplified fragments are indicated on the right. Molecular sizes (in base pairs) are given on the left.