Dear Bioconductor, Can anyone suggest a different way to incorporate both the biological and technical reps with this loop design? There are three strains (C,H,V), 2 treatments (W,D), and 3 bioreps per strain/treatment (1,2,3). There are 2 tech reps per biological replicate. Slide Cy3 Cy5 1 V3W H2W 2 H2W H1D 3 H2D H1W 4 V3D H2D 5 C1D H3D 6 C1W H3W 7 V2W V1D 8 V2D V1W 9 C3D V2D 10 C3W V2W 11 H1W V3W 12 H3D V3D 13 C2W C1D 14 H1D C2D 15 C2D C1W 16 V1W C2W 17 V1D C3D 18 H3W C3W I've yet to find a way that works. Thank you for addressing this. -Heather