Please Contact WPI for Pricing

Order code
  • Two photomultiplier inputs
  • Light excitation with high-power LEDs
  • Low bleaching mode (5% LED on time)
  • Automatic LED light drift correction for long term measurements
  • Automatic room light correction
  • Up to four modes of fluorescence detection of indicator dyes and natural fluorophores
    • Single excitation / single emission
    • Dual excitation / single emission
    • Single excitation / dual emission
    • Dual excitation / dual emission
  • Optical connections: Liquid Light Guides (LLGs) or SMA terminated fibers
  • Sampling rates up to 1 kHz (1000 ratios / sec)
  • Versatile instrument for horizontal tissue bath, Langendorff and microscope applications
  • Can be combined with imaging based Sarcomere Detection System (OptiSarc)
  • Customized analysis techniques in WPI's MDAC data acquisition software

Current data sheet


  • Exchangeable high-power LED modules to reduce the optical demands of the setup
  • Optical fiber combiner to mix up to three LED modules
  • High sensitive optical fibers and photomultiplier modules in single or dual wavelength detection
  • Easy and time-saving changes of the optical setup to full-fil the fluorescent requirements of specific fluorophores
  • Inexpensive high-power LED modules and sensitive photomultiplier modules allow for detecting of even weak fluorescence signals
  • Direct ratiometric measurements to cancel out possible effects of uneven loading, inhomogeneous distribution of fluorescence indicator in the cells or indicator bleaching
  • Multiple connections for direct sensing of the fluorescence signal from tissue samples or imaging fluorescence via epi-fluorescence input port or c-mount terminated output port of a fluorescence microscope
  • High sample rates to capture with high fidelity the kinetics of ion transients
  • Application-specific probes are available for existing tissue baths and cuvette systems
  • Ratio noise is <0.05 peak to peak; drift is less than 0.1 unit/hour
  • The warm up time of less than one minute is a dramatic improvement over the common 20–60 minutes required by xenon or mercury light sources
  • Replace the emission filter easily or change the high-power LED modules to transform the SI-BF-100 into a general purpose fluorometer for many other applications

The video below discusses some of the benefits of this unique fluorometer (6 minutes).

The new SI-BF-100 is an LED-based fluorometer for life science applications. It is ideally suited for ratiometric calcium detection (e.g. Fura-8) and ATPase detection (via NADH fluorescence). With up to three high-power LED modules (wavelengths), the SI-BF-100 covers many fluorometric applications in muscle physiology, neuroscience and cell biology.SI-BF100 is an LED-based fluorometer

Unique fiber optic coupling probe allows for highly efficient transfer of light and ease of placement. Custom probes fit your existing systems.


WPI developed a fiber optic based Biofluorometer (SI-BF-100) for physiological research. The instrument features the use of up to three exchangeable high-power LED modules as excitation source and two highly sensitive photomultiplier modules (PMT’s), allowing the detection of weak fluorescent signals.

The use of fluorescence for sensing and imaging of the cellular signaling pathways has emerged an indispensable tool in modern physiology providing dynamic information of quantity and localization of the molecules of interest. Using appropriate indicator dyes, molecules alter their fluorescent characteristics in response to ion binding or membrane integration, so that the optical signal from the indicator dye can be measured to monitor the amplitude and the time course of various metal ions like Na+, K+, Mg2+ and Ca2+, as well as pH and membrane potential in cellular compartments.

The Biofluorometer opens a wide field in functional fluorescence research, by studying the fundamental and/or applied aspects of the underlying energetics and signaling aspects of muscle contraction. This is notably useful in:

  • Pre-clinical & toxicological studies:
    • Screening of potential drugs
    • Evaluating models of cardiac disease
    • Evaluating the effects of muscle dystrophies/myopathies
  • Sports & rehabilitation:
    • Disuse overuse
    • Muscle damage
    • Function of transplanted heart

System Configuration

  • SI-BF-100 Biofluorometer, with high-power LEDs in UV and VIS range
  • Selectable & exchangeable Emission filters, adapted to used molecule/indicator dye
  • Selectable & exchangeable high-power LED’s, adapted to used molecule/indicator dye
  • SI-MT Muscle Tester System or SI-HTB2 Tissue Bath
  • LabTrax 8/16 with MDAC
  • Option: Euromex Inverted Microscope

How it Works

Excitation light is guided from the SI-BF-100 light output to the tissue/cell sample and emission light from the tissue/cell sample to the PMT modules using optical fibers, with so-called liquid light guides (LLGs) or SMA terminated connections. Such an optical setup allows direct and simple connection to a microscopic set-up or a variety of imaging probes situated inside or adjacent to a tissue bath (WPI’s SI-MT or SI-HTB2).  Furthermore, the emitting fluorescent signal can be measured directly and displayed via a data acquisition system (like WPI´s LabTrax 8/16 with MDAC), allowing the quantification of rapidly changing temporal events, e.g. transients in the concentration of free calcium (Δ[Ca2+]).


Monochromatic LED light sources using WPI patented technology eliminate the need for complex and expensive white light sources and filter wheels. Because the high-power LED modules can be pulsed, sampling frequencies up to 1,000 cycles per second are possible. The LED light source emits specific excitation frequencies which travel through the probe. The excitation light can be comprised of any wavelength of light for which a high-power LED module is available. The probe returns a single emission output to one or two photomultiplier inputs on the front of the SI-BF-100, which are independently filtered for specific wavelengths. This design allows you to monitor multiple wavelengths from a single emission output. The LED light source in the WPI design makes this ratiometric fluorometer more compact, energy efficient and affordable. WPI’s Biofluorometer (SI-BF-100) was specifically developed to monitor rapid changes, e.g. in Δ[CA2+], using high-power LED modules, optical fiber combiner and highly sensitive photomultiplier modules to detect even very weak fluorescent signals at sample rates of 1,000 ratios/s.

Ca2+Excitation Wavelength 365, 410 nm for Fura-8 (others available)
Ca2+Emission Wavelength 525nm (others available)
ATPase (NADH) Excitation Wavelength 360nm (others available)
ATPase (NADH) Emission Wavelength 470nm, 570nm (others available)
Fiber Optic Light Input/Output LLG or SMA terminated
Sampling rate Up to 1000 ratios/second
Ratio Noise < 0.5 peak-to-peak
Signal Drift < 0.1 unit/hours
Analog Output Range 0–10V (continuous, equivalent to a ratio 0–10)
Analog Output Impedance 100Ω
Power 12VDC, 0.5A, (universal power supply, 110/240VAC)
Warm Up Time  
Dimensions 3.5"H x 17"W x 13"D (88 x 431 x 330mm)


Belz, M., Dendorfer, A., Werner, J., Lambertz, D., & Klein, K.-F. (2016). Fiber optic biofluorometer for physiological research on muscle slices. In I. Gannot (Ed.), SPIE BiOS (p. 97020Q). International Society for Optics and Photonics.


Copyright © World Precision Instruments. All rights reserved.