Stylized depiction of the interaction of a scorpion toxin (indicated by the unique shape of the claws) with the S3b–S4 paddle motif of a Nav channel attached to an SPR chip. Polarized light to measure the refractive index near the sensor surface to which the paddle motif is attached is depicted below the chip. See Martin-Euclaire et al. (2015). Image provided by Kate Baldwin (http://www.k8baldwin.com/).
