Non-specific probe binding to the shell field and radular is eliminated by treatment with TEAAA. We observe a well-defined and consistent WMISH stain for a variety of probes (represented here with a probe against the gene “contig 380566”) in the periphery of the shell field (arrows in B and C) and in the radular sac (arrow in D). Probes against other genes (for example beta tubulin) do not produce these patterns (A). The stain in the shell field periphery and the radular remains following a pre-hybridisation treatment with RNAse (F-H), while the specific signal against beta tubulin is abolished (E). This indicates that the signals in the shell field and the radular are the result of non-specific probe binding. Treatment with TEAAA abolishes this non-specific stain (J-L), while the specific signal against beta tubulin remains unaltered (I). B, F and J are dorsal views. A, C, E, G, I and K are lateral views of larvae with the shell gland oriented to the right. D, H and L are ventral views. Panels C, G and K are reflected about the vertical axis for consistency of presentation.