New IR marker enables advanced bioimaging

Scientists at the Helmholtz Zentrum München have developed an infrared (IR) fluorescent protein marker to improve the quality of tissue imaging.

Scientists at the Helmholtz Zentrum München (Oberschleißheim, Germany) have developed an infrared (IR) fluorescent protein marker to improve the quality of tissue imaging. Dubbed Amrose, the new marker is now being used for advanced near-IR bioimaging procedures.

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Far-red shifted fluorescent tissue markers make it possible to visualize structures and processes with advanced bioimaging. This permits new insights into organisms and creates the potential for a wide range of applications, from more exact delineation of tumor and metastasis to tracking drug responses within whole-body imaging.

The team of scientists, headed by Dr. Ulrike Schoetz, Dr. Nikolas Deliolanis, Dr. Wolfgang Beisker, Prof. Horst Zitzelsberger, and Randolph Caldwell, have succeeded in developing novel fluorescent markers that excite in the far-red and emit in the IR spectrum. Depending on the light spectrum used and the organism under examination, these can now deliver better-quality images. The tests confirming the spectral properties were conducted in cooperation with the Max Planck Institute for Neurobiology (Martinsried) and the Federal Institute for Materials Research and Testing (Berlin).

A high level of diversification occurs naturally in the B cells of the immune system, which produce antibodies. When genetic material is introduced into these cells, this evolutionary mechanism can be co-opted to create new genetic and protein variants. The scientists were thus able to transfer the genetic information from the known fluorescent protein eqFP615 into the DT40 chicken B cell line to produce protein variants of Amrose with different spectral properties.

Full details of the work appear in the journal PLoS One; for more information, please visit


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