Optical Radiology Labs at Washington University in St. Louis School of Medicine

Fluorescence Lifetime Imaging Microscope system, MicroTime 200, PicoQuant: NIH resource

We have recently installed (Aug., 2014) a unique Fluorescence Lifetime Imaging Microscopy (FLIM) System, MicroTime 200 from PicoQuant. The instrument was purchased from funding provided by NIH (S10 Shared Instrumentation Grant). This system built by PicoQuant is one of the most sophisticated FLIM systems in the world. Very soon, you can use this system for your research with a small fee to support the maintenance cost. This system is part of our Washington University's Optical Imaging Core Facility.


Our MicroTime 200 system is available to serve the needs of the imaging community in greater St. Louis. Send us lab sample or schedule a visit (you might need to select the instrument from the dropdown menu of "View Schedule").


General description

The fluorescence lifetime (FLT) of a fluorophore is the average time a molecule spends in the excited state between absorption and emission of radiation. FLT information complements that of conventional fluorescence intensity measurement derived from single- or multi-photon mechanism. Fluorescence intensity measures molecular processes in cells or small animals encoding fluorescent proteins or labeled with exogenous fluorescent dyes. In contrast, FLT based techniques provide information of a target biomolecule or process in response to the cellular microenvironmental changes stimulated by several factors such as pH, lipophilicity, cell metabolic state, presence of free radicals, and hypoxia. Moreover, the sensitivity of FLT to microenvironments can be harnessed through other photophysical mechanisms, including fluorescence resonance energy transfer (FRET), to report specific molecular processes and interactions. 

Our MicroTime 200 system allows imaging at diverse wavelengths (485, 510, 640, 785 nm) using dyes with lifetime ranging from 500 ps - 100 ns, detects simultaneously in two separate channels, and provides user-friendly interface. Additional benefit of the system includes its feasibility of adapting it to other techniques such as fluorescence (cross-) correlation spectroscopy (F(C)CS), fluorescence lifetime (cross-) correlation spectroscopy (FL(C)CS), and lifetime-based FRET, which together further enhances the information content of cellular processes available to the users.   

Additional information in tutorial format is available at PicoQuant website.

Representative images

Two examples of FLT dependence on the local environment. A) Overview of HepG2 cells labeled with NBD tagged phosphlipids. The vacuole is enriched with fluorescent phospholipids. The lifetime difference with other compartments is clearly visible and provides information about the membrane structure. B) & C) Dissected salivary glands of an American cockroach, labeled with MQAE and placed in buffers with 174 mM NaCl (B) and 2 mM NaCl (C). Courtesy of Carsten Hille, Carsten Dosche, Potsdam University.


FLIM-FRET measurements of the human kinetochore proteins CENP- A and CENP-B. FLIM images of human U2OS cells transfected with the donor CENP-B-Cerulean (A) or additionally with the acceptor EYFP-CENP-A (B) display the donor FLT (Single channel detection). The blue decay curve in the TCSPC histogram (C) corresponds to the three blue- circled centromeres of the control cell (A), whereas the green and red lines represent fluorescence decays of the indicated centromeres in the FRET cell (B). The FLT is indicated by a false color representation.

We offer

  • Hands-on education and seminar on FLIM 
  • Bench space to prepare the samples 
  • Collaborative research opportunities 
  • Data interpretations and recommendations


Becoming a user

Any prospective FLIM users (PIs, post-docs, staff scientists, lab technicians, students, university employees, private industry, government, etc.) should contact the PI Prof. Samuel Achilefu (achilefus@mir.wustl.edu) and copy Ms. Rebecca Gilson (rebecca.gilson@wustl.edu).

Local advisory committee

  • Robert Gropler, MD, Professor of Radiology and Director of Radiological Sciences Division of MIR (groplerr@mir.wustl.edu)
  • Joseph Ackerman, PhD, Professor of Chemistry, Radiology, and Molecular Biophysics (ackerman@wustl.edu)
  • Timothy Holy, PhD, Associate Professor of Anatomy and Neurobiology (holy@wustl.edu)


User fees ($ per h, 1 h min)

From Universities

8 am -  6 pm

6 pm-8 am


Users (≥10 hrs/month)




Users (<10 hrs/month)




Non NIH funded users




Extra fee for assisted experiments




Other fees:

  • Mandatory training: $50/h (2 h min) 
  • Industry users: Add 80% to the price list 
  • Assistance with sample preparation: $40/h (1 h min) 
  • Assistance with data analysis: $50/h (1 h min) 
  • Assistance with report preparation: $100/h (1 h min)



All work performed on this instrument should be acknowledged in scholarly reports, presentations, posters, papers, and all other publications. We suggest the following language:

This research was supported by the Optical Imaging Core Facility of Washington University School of Medicine, and a shared Fluorescence Lifetime Imaging Microscopy system (MicroTime 200, PicoQuant) obtained through NIH Shared Instrumentation Grant (1 S10 OD016237-01).

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©2011 Mallinckrodt Institute of Radiology     Last Modified on February 16th