A new line of red-shifted fluorescent tissue markers may enhance deep-tissue imaging. A team from the German Research Center for Environmental Health, in collaboration with the Max Planck Institute for Neurobiology and the Federal Institute for Materials Research and Testing, developed the markers, which are excited by yellow and red light and emit light toward the far-red region of the spectrum. The markers were created by introducing genetic information from the fluorescent protein eqFP615 into a DT40 chicken immune B cell line. The markers’ responses were tested in zebrafish and mouse models. The marker accesses emission wavelengths optimal for whole-body and deep tissue imaging, the researchers said. “Here we have demonstrated the further use of this novel technology to develop highly sought-after, biologically relevant fluorescent markers quickly and easily for different imaging needs,” said Randolph Caldwell, a researcher at the German Research Center. The new markers offer expanded insight into organisms and offer the potential for more exact delineation of tumor and metastasis, as well as tracking drug responses within whole-body imaging, the researchers said. The research was published in PLOS One (doi: 10.1371/journal.pone.0107069). For more information, visit www.helmholtz-muenchen.de.