OptiMiS encapsulates technology, developed by Dr. Valerică Raicu’s research group at UWM, that produces spectrally resolved fluorescence images of living cells using a multi-photon microscope (MPM) after only one full scan of the sample. MPM microscopes equipped with the OptiMiS system will allow acquisition speed and spectral resolution to permit investigations of highly dynamic living cells. Using a prototype OptiMiS installed in his laboratory, Raicu’s group was able, for the first time in published literature, to determine the structure of protein complexes in living cells by employing the principles of Fluorescence Resonance Energy Transfer (FRET). Management expects the same technology can be used to detect even transient interactions between proteins inside the living cells. In addition, it is possible to use this technology in any other biological investigation that requires one to use multiple fluorescent tags, such as in protein co-localization studies. The impact of this advancement expands the marketplace for MPM systems to include laboratories whose focus of research is on cell receptors. This has the potential of doubling the size of the market for these systems overnight as these researchers do not use any fluorescent microscope systems in their research at this time.

This technology presents the following unique capabilities, when compared to other techniques:

  • Determination of the entire spectral fingerprint of the chemical species contained in a small sample voxel at once for all emission wavelengths investigated, thereby allowing one to perform molecular imaging;
  • High efficiency of the dispersed light;
  • Single-photon detection limit;
  • Faster acquisition speed;
  • Simplicity, that is, robustness in operation and reliability.

PowerPoint Presentation of an Overview of OptiMis Technology
by Dr. Valeria Raicu:


Relevant Scientific Publications

Stoneman, M., Singh, D., Raicu, V., In vivo Quantification of G Protein Coupled Receptor Interactions using Spectrally Resolved Two-photon Microscopy doi: 10.3791/2247. J Vis Exp. 47 (2011).

V. Raicu “FRET-based determination of protein complex structure at nanometer length scale in living cells” In: A. Diaspro (Editor), Nanoscopy. Multidimensional Optical Fluorescence Microscopy, CRC Press (2010)

D.R. Singh, V.Raicu, Comparison between whole-distribution- and average-based approaches to the determination of FRET efficiency in ensembles of proteins in living cells, Biophysical Journal,98 (2010) 2127-2135.

Valerica Raicu, Michael R. Stoneman, Russell Fung, Mike Melnichuk, David B. Jansma, Luca F. Pisterzi, Sasmita Rath, Michael Fox, James W. Wells and Dilano K. Saldin. Determination of Supramolecular Structure and Spatial Distribution of Protein Complexes in Living Cells. Nature Photonics | VOL 3 | Februrary 2009 pp 107-113.
Click here to read article

Giuseppe Chirico News and Views: Bioimaging: Protein Watching
Nature Photonics | VOL 3 | February 2009 pp 81-82

Valerică Raicu, Russell Fung, Mike Melnichuk, Anurag Chaturvedi, Devin Gillman
Combined Spectrally-Resolved Multiphoton Microscopy and Transmission Microscopy Employing a High-Sensitivity Electronmultiplying CCD Camera
Multiphoton Microscopy in the Biomedical Sciences VII, edited by Ammasi Periasamy, Peter T. C. So, Proc. of SPIE Vol. 6442, 64420M, (2007) pp 1605-7422