The K2 family of frequency-domain fluorometers provides researchers with a solid, well-proven instrumentation platform for the most demanding fluorescence and phosphorescence applications.

With installed units all over the world, the K2 family of Multifrequency Cross-Correlation Phase and Modulation Fluorometers represents a solid and well-proven approach to fluorescence and phosphorescence instrumentation for the research laboratory. The K2 is used by researchers at the ETH in Zurich, Switzerland, the MIT in Cambridge, MA, the NIH in Rockville, MD, and at the NASA research facility in Huntsville, AL.

Its optical design and automatic instrument control are state-of-the-art for steady-state and time-resolved fluorescence measurements. Full automation and the user-friendly Vinci software package make the instrument easy to use for both, the student and the scientist.

Key features of K2 include:

  • Lifetime measurement capabilities from 1 millisecond to 1 picosecond
  • Complete lifetime scans in less than one minute on routine samples with proprietary FastScan technology
  • A compact footprint and a short optical pathlength for maximum sensitivity and efficient light coupling into the sample
  • T-format and parallel beam optical design for fast and precise polarization measurements
  • Full automation of all instrument components (cuvette holder, polarizers, shutters, filterwheel, monochromators, and stirrers)
  • PC-controlled integration of temperature bath, titrator, stopped-flow apparatus and pressure pump
  • Measurement of fast kinetics data with one millisecond resolution in photon counting mode
  • 80 MHz pre-amplifier discriminators delivering linearity up to over eight million counts per second on each channel
  • Flexible instrument configuration
  • Upgradeable with Ti:Sapphire laser and laser diodes

Three models of K2 are available, and each comes fully automated and upgradeable.

K2-001 with K2 FastScan
The FastScan is our most popular model: lifetime data acquisition on a routine sample can be acquired in less than one minute using either a lamp or a laser. The cross-correlation is user-selectable up to 5,000Hz and data acquisition is performed through a FFT routine; the instrument covers the modulation frequency range from 300KHz up to 350MHz with a lamp and up to 450MHz using a cw laser.

K2-002 1.2GHz Upgrade
This model requires a mode-locked laser as excitation source and a microchannel plate detector (MCP-PMT) for the collection of fluorescence. Alternatively, a laser diode can be utilized as the light source to measure frequency responses up to about 1GHz. The cross-correlation is user-selectable up to 5,000Hz and data acquisition is performed through a FFT routine. It includes the FastScan upgrade and operates at modulation frequency up to 1.2GHz.

K2-003 6GHz Upgrade
The K2-003 is an upgrade of the K2-002: it operates in the frequency range up to 6GHz.

New Digital Frequency Domain Technology

Specifications for K2

Measurements (Steady-State Fluorescence) • Corrected excitation and emission spectra
• Excitation-emission matrices
• Polarization (anisotropy) measurements
• Millisecond kinetics in photon counting mode
• Dual-wavelength-ratiometric excitation or emission measurements
Measurements (Time-Resolved Fluorescence)

• Multiple decay times from millisecond to picosecond time scale
• Anisotropy decays
• Phase- and modulation-resolved spectra (up to 3 components in a mixture)
• Time-resolved spectra

Light Sources • 300 W xenon arc lamp, 45 mW/nm brightness at 275 nm
• Laser diodes
• Light emitting diodes (LEDs)
• Continuous wave lasers (argon-ion, krypton-ion, helium-cadmium)
• Mode-locked lasers (Ti:Sapphire)
• Synchrotron light beams
Monochromators Single concave holographic grating Wavelength range: from 200 nm to 1200 nm (dependent on selected grating)
Detectors • Selected side-on photomultiplier tubes in room-temperature or cooled housing (for frequency response up to 800 MHz)
• Microchannel plate detectors (for frequency response > 800 MHz)
• Optional: CCD camera
Detection Modes • Photon counting electronics, 10 KHz, on 3 independent channels
• Analog Output on 3 channels
Frequency-Response From DC up to 10 GHz
Frequency Synthesizers • Marconi Instruments
• Programmed Test Sources
• Gigatronics
• Hewlett Packard
Light Modulation • Wide aperture Pockels cell (for lamp and cw lasers) up to 350 MHz
• Direct modulation (for laser diodes and LEDs) up to 700 MHz
• Harmonic content of pulsed sources up to 10 GHz
Polarizers • UV-grade Glan-Thompson, 10x10 mm, L/A=2.0
• UV-grade Glan-Thompson, 14x14 mm, L/A=2.0
• UV-grade Glan-Taylor, 10x10 mm, L/A=2.0 (for high power lasers)
Pre-Amplifier Discriminators 100 MHz bandwidth, TTL output
Focusing and Collection Geometry Parallel beam design for precise polarization measurements
Dynamic Range Linear up to 4 million counts/second
Wavelength Accuracy ±0.2 nm
Wavelength Reproducibility ±0.25 nm
Slew Rate 160 nm/s (optional double grating)
Lifetime Measurements Range From 100 millisecods to 20 picoseconds (depending upon the model; the shortest measurable decay time is determined by the light detectors frequency response)
OS Requirements Windows 10
Power Requirements Universal power input: 110-240 V, 50/60 Hz, 400 VAC
Dimensions 885 mm (L) x 600 mm (W) x 330 mm (H)
Weight 45 kg

Schematic Diagram for K2

Measurement Examples from K2

2-Aminopurine in Water

Frequency responses (phase and modulation) of 2-Aminopurine in water acquired on K2 using a Xenon lamp. The excitation wavelength was 290-nm with a 2 mm slit size. The emission was collected through a 345 high pass filter. The data is best fitted with a single exponential decay time of 11.69 ns (θ2 = 1.32).

Rose Bengal in Water

Time-domain anisotropy decays of Rose Bengal in water acquired on ChronosBH using a 447-nm pulsed laser diode. The emission was collected through a long pass filter KV 505. Calculated values for θ = 0.16 ns with R0 = 0.39 and τ = 0.075 ns, T = 20-21°C.

Biochemistry & Molecular Biology (Membranes, Nucleic Acids, Proteins)

Sometimes It Takes Two to Tango: Contributions of Dimerization too Functions of Human α-defensin HNP1 Peptide
Pazgier, M., Wei, G., Ericksen, B., Jung, G., Wu, Z., de Leeuw, E., Yuna, W., Szmacinski, H., Lu, W.-Y., Lubkowski, J., Lehrer, R.I., Lu, W.
J Biol Chem, 2012, 287(12), 8944-8953.
Targeting TLR4 Signaling by TLR4 TIR-derived Decoy Peptides: Identification of the TLR4 TIR Dimerization Interface
Toshchakov, V.Y., Szacinski, H., Couture, L.A., Lakowicz, J.R., Vogel, S.N.
J Immunol, 2011, 186(8), 4819-4827.
A New Competitive Fluorescence Assay for the Detection of Patulin Toxin
de Champdoré, M., Bazzicalupo, P., De Napoli, L., Montesarchio, D., Di Fabio, G., Cocozza, I., Parracino, A., Rossi, M., D'Auria, S.
Anal. Chem., 2007, 79, 751-757.
Fluorescence of Amphotericin B-Deoxycholate (Fungizone) Monomers and Aggregates and the Effect of Heat-Treatment
Stoodley, R., Wasan, K.M., Bizzotto, D.
Langmuir, 2007, 23(17), 8718-8725.
Structural Dynamics of the Actin–Myosin Interface by Site-Directed Spectroscopy
Korman, V.L., Anderson, S.E.B., Prochniewicz, E., Titus, M.A., Thomas, D.D.
Journal of Molecular Biology, 2006, 356(5), 1107-1117.
Genetic and Fluorescence Studies of Affinity Maturation in Related Antibodies
Pauyo, T., Hilinski, G.J., Chiu, P.T., Hansen, D.E., Choi, Y.J., Ratner, D.I., Shah-Mahoney, N., Southern, C.A., O'Hara, P.B.
Molecular Immunology, 2006, 43(7), 812-821.
A Fluorescence Spectroscopy Study on the Interactions of the TAT-PTD Peptide with Model Lipid Membranes
Tiriveedhi, V., Butko, P.
Biochemistry, 2007, 46, 3888-3895.
IIAGlc Inhibition of Glycerol Kinase: A Communications Network Tunes Protein Motions at the Allosteric Site
Yu, P., Lasagna, M., Pawlyk, A.C., Reinhart, G.D., Pettigrew, D.W.
Biochemistry, 2007, Printing Pending.
Inhibition of Amyloid Fibril Formation and Cytotoxicity by Hydroxyindole Derivatives
Cohen, T., Frydman-Marom, A., Rechter, M., Gazit, E.
Biochemistry, 2006, 45, 4727-4735.
Phosphorylation of a Single Head of Smooth Muscle Myosin Activates the Whole Molecule
Rovner, A.S., Fagnant, P.M., Trybus, K.M.
Biochemistry, 2006, 45, 5280-5289.
Expression and Physicochemical Characterization of an Extracellular Segment of the Receptor Protein Tyrosine Phosphatase IA-2
Primo, M.E., Sica, M.P., Risso, V.A., Poskus, E., Ermácora, M.R.
Biochimica et Biophysica Acta (BBA) - Proteins & Proteomics, 2006, 1764(2), 174-181.
Structural Characterization of Novel Chitin-Binding Lectins from the GenusArtocarpus and Their Antifungal Activity
Trindade, M.B., Lopes, J.L.S., Soares-Costa, A., Monteiro-Moreira, A.C., Moreira, R.A., Oliva, M.L.V., Beltramini, L.M.
Biochimica et Biophysica Acta (BBA) - Proteins & Proteomics, 2006, 1764(1), 146-152.
Direct Detection of Calmodulin Tuning By Ryanodine Receptor Channel Targets Using a Ca2+-Sensitive Acrylodan-Labeled Calmodulin
Fruen, B.R., Balog, E.M., Schafer, J., Nitu, F.R., Thomas, D.D., and Corena, R.L.
Biochemistry, 2005, 44, 278-284.
Reductive and Oxidative DNA Damage by Photoactive Platinum(II) Intercalators
Lu, W., Vicic, D.A., Barton, J.K.
Inorg. Chem., 2005, 44(22), 7970-7980.
Improved "Optical Highlighter" Probes Derived from Discosoma Red Fluorescent Protein
Robinson, L.C.
Biophys. J., 2005, 88, 1444-1457.
Essential Role for Pro21 in Phospholamban for Optimal Inhibition of the Ca-ATPase
Li, J., Boschek, C.B., Xiong, Y., Sacksteder, C.A., Squier, T.C., Bigelow, D.J.
Biochemistry, 2005, 44(49), 16181-16191.
Sequence-Specific Fluorescence Detection of DNA by Polyamide-Thiazole Orange Conjugates
Fechter, E.J., Olenyuk, B., Dervan, P.B.
J. Am. Chem. Soc., 2005, 127(47), 16685-16691.
Ethanol-Perturbed Amyloidogenic Self-Assembly of Insulin: Looking for Origins of Amyloid Strains
Dzwolak, W., Grudzielanek, S., Smirnovas, V., Ravindra, R., Nicolini, C., Jansen, R., Loksztejn, A., Porowski, S., Winter, R.
Biochemistry, 2005, 44(25), 8948-8958.
Probing the Interior of Peptide Amphiphile Supramolecular Aggregates
Tovar, J.D., Claussen, R.C., Stupp, S.I.
J. Am. Chem. Soc., 2005, 127(20), 7337-7345.
Reductive and Oxidative DNA Damage by Photoactive Platinum(II) Intercalators
Lu, W., Vicic, D.A., Barton, J.K.
Inorg. Chem., 2005, 44(22), 7970-7980.
Structural Uncoupling between Opposing Domains of Oxidized Calmodulin Underlies the Enhanced Binding Affinity and Inhibition of the Plasma Membrane Ca-ATPase
Chen, B., Mayer, M.U., Squier, T.C.
Biochemistry, 2005, 44(12), 4737-4747.
Trans Fatty Acid Derived Phospholipids Show Increased Membrane Cholesterol and Reduced Receptor Activation as Compared To Their Cis Analogs
Niu, S.-L., Mitchell, D.C., Litman, B.J.
Biochemistry, 2005, 44(11), 4458-4465.
Phospholamban Pentamer Quaternary Conformation Determined by In-Gel Fluorescence Anisotropy
Robia, S.L., Flohr, N.C., Thomas, D.D.
Biochemistry, 2005, 44(11), 4302-4311.
Oligomeric State and Mode of Self-Association ofThermotoga maritima Ribosomal Stalk Protein L12 in Solution
Moens, P.D.J., Wahl, M.C., Jameson, D.M.
Biochemistry, 2005, 44(9), 3298-3305.
Dynamic Motion of Helix A in the Amino-Terminal Domain of Calmodulin Is Stabilized upon Calcium Activation
Chen, B., Mayer, M.U., Markillie, L.M., Stenoien, D.L., Squier, T.C.
Biochemistry, 2005, 44(3), 905-914.
Interaction of the 20 kDa and 63 kDa Fragments of Anthrax Protective Antigen: Kinetics and Thermodynamics
Christensen, K.A., Krantz, B.A., Melnyk, R.A., Collier, R.J.
Biochemistry, 2005, 44(3), 1047-1053.
A Detergent-like Mechanism of Action of the Cytolytic Toxin Cyt1A fromBacillus thuringiensis var.israelensis
Manceva, S.D., Pusztai-Carey, M., Russo, P.S., Butko, P.
Biochemistry, 2005, 44(2), 589-597.
Structural Uncoupling between Opposing Domains of Oxidized Calmodulin Underlies the Enhanced Binding Affinity and Inhibition of the Plasma Membrane Ca-ATPase
Chen, B., Mayer, M.U., Squier, T.C.
Biochemistry, 2005, 44(12), 4737-4747.
Reductive and Oxidative DNA Damage by Photoactive Platinum(II) Intercalators
Lu, W., Vicic, D.A., Barton, J.K.
Inorg. Chem., 2005, 44(22), 7970-7980.
Probing the Interior of Peptide Amphiphile Supramolecular Aggregates
Tovar, J.D., Claussen, R.C., Stupp, S.I.
J. Am. Chem. Soc., 2005, 127(20), 7337-7345.
Complex Formation Between Plasmid DNA and Self-Aggregates of Deoxycholic Acid-Modified Chitosan
Lee, K.Y., Kwon, I.C., Jo, W.H., Jeong, S.Y.
Polymer, 2005, 46(19), 8107-8112.
Heterologous Expression, Characterization and Structural Studies of a Hydrophobic Peptide from the HIV-1 p24 Protein
Castilho, P.V., Campana, P.T., Garcia, A.F., Beltramini, L.M., Araújo, A.P.U.
Peptides, 2005, 26(2), 243-249.
Conformation of a Synthetic Antigenic Peptide from HIV-1 p24 Protein Induced by Ionic Micelles
Campana, P.T., Beltramini, L.M., Costa-Filho, A.J., Tonarelli, G., Lottersberger, J., Bianconi, M.L.
Biophysical Chemistry, 2005, 113(2), 175-182.
A Nature of Conformational Changes of Yeast tRNAPhe: High Hydrostatic Pressure Effects
Giel-Pietraszuk, M., Barciszewski, J.
International Journal of Biological Macromolecules, 2005, 37(3), 109-114.
Calcium Activation of the Ca-ATPase Enhances Conformational Heterogeneity between Nucleotide Binding and Phosphorylation Domains
Chen, B., Squier, T. C., Bigelow, D. J.
Biochemistry, 2004, 43(14), 4366-4374.
Conformational Changes within the Cytosolic Portion of Phospholamban upon Release of Ca-ATPase Inhibition
Li, J., Bigelow, D. J., Squier, T. C.
Biochemistry, 2004, 43(13), 3870-3879.
Correlation between Mechanical and Enzymatic Events in Contracting Skeletal Muscle Fiber
Shepard, A., Borejdo, J.
Biochemistry, 2004, 43(10), 2804-2811.
Cholesterol Superlattice Modulates the Activity of Cholesterol Oxidase in Lipid Membranes
Wang, M. M., Olsher, M., Sugar, I. P., Chong, P. L.-G.
Biochemistry, 2004, 43(8), 2159-2166.
Phospholamban Binds in a Compact and Ordered Conformation to the Ca-ATPase
Li, J., Xiong, Y., Bigelow, D. J., Squier, T. C.
Biochemistry, 2004, 43(2), 455-463.
Partitioning of Dual-Lipidated Peptides into Membrane Microdomains: Lipid Sorting vs Peptide Aggregation
Janosch, S., Nicolini, C., Ludolph, B., Peters, C., Volkert, M., Hazlet, T. L., Gratton, E., Waldmann, H., Winter, R.
J. Am. Chem. Soc., 2004, 126(24), 7496-7503.
Direct Detection of Phospholamban and Sarcoplasmic Reticulum Ca-ATPase Interaction in Membranes Using Fluorescence Resonance Energy Transfer
Mueller, B., Karim, C. B., Negrashov, I. V., Kutchai, H., Thomas, D. D.
Biochemistry, 2004, 43(27), 8754-8765.
DNA Charge Transport: Conformationally Gated Hopping through Stacked Domains
O'Neill, M. A., Barton, J. K.
J. Am. Chem. Soc., 2004, 126(37), 11471-11483.
Short-Lived Fluorescence Component of DPH Reports on Lipid-water Interface of Biological Membranes
Konopásek, I., Vecer, J., Strzalka, K., Amler, E.
Chemistry and Physics of Lipids, 2004, 130, 135-144.
A Recombinant Glutamine-Binding Protein fromEscherichia coli: Effect of Ligand-Binding on Protein Conformational Dynamics
Herman, P., Vecer, J., Scognamiglio, V., Staiano, M., Rossi, M., D'Auria, S.
Biotechnol. Prog., 2004, 20(6), 1847-1854.
High Hydrostatic Pressure Perturbs the Interactions between CF0F1 Subunits and Induces a Dual Effect on Activity
Souza, M.O., Creczynski-Pasa, T.B., Scofano, H.M., Gräber, P., Mignaco, J.A.
The International Journal of Biochemistry & Cell Biology, 2004, 36(5), 920-930.
Conformational and Enzymatic Changes of 20S Proteasome of Rat Natural Killer Cells Induced by Mono- and Divalent Cations
Reshetnyak, Y.K., Kitson, R.P., Lu, M., Goldfarb, R.H.
Journal of Structural Biology, 2004, 145(3), 263-271.
Effects of Ethanol on Lipid Bilayers with and without Cholesterol: The Distearoylphosphatidylcholine System
Tran, R., Ho, S., Dea, P.
Biophysical Chemistry, 2004, 110(1-2), 39-47.
Cloning and Characterization of the cDNA for the Brazilian Cratomorphus distinctus Larval Firefly Luciferase: Similarities with European Lampyris noctiluca and Asiatic Pyrocoelia luciferases
Viviani, V.R., Arnoldi, F.G.C., Brochetto-Braga, M., Ohmiya, Y.
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 2004, 139(2), 151-156.
Characterization of Lecithin: Cholesterol Acyltransferase Expressed in a Human Lung Cell Line
Lane, S.B., Tchedre, K.T., Nair, M.P., Thigpen, A.E., Lacko, A.G.
Protein Expression and Purification, 2004, 36(2), 157-164.
Sequence Specific Fluorescence Detection of Double Strand DNA
Rucker, V.C., Foister, S., Melander, C., Dervan, P.B.
J. Am. Chem. Soc., 2003, 125(5), 1195-1202.
Surface Changes and Role of Buried Water Molecules during the Sulfane Sulfur Transfer in Rhodanese and Azotobacter vinelandii: A Fluorescence Quenching and Nuclear Magnetic Relaxation Dispersion Spectroscopic Study
Fasano, M., Orsale, M., Melino, S., Nicolai, E., Forlani, F., Rosato, N., Cicero, D., Pagani, S., Paci, M.
Biochemistry, 2003, 42, 8550-8557.
Phosphorylation by cAMP-Dependent Protein Kinase Modulates the Structural Coupling between the Transmembrane and Cytosolic Domains of Phospholamban
Li, J., Bigelow, D. J., Squier, T. C.
Biochemistry, 2003, 42(36), 10674-10682.
Evidence for Tryptophan Residues in the Cation Transport Path of the Na+,K+-ATPase
Yudowski, G. A., Bar Shimon, M., Tal, D. M., Gonzalez-Lebrero, R. M., Rossi, R. C., Garrahan, P. J., Beauge, L. A., Karlish, S. J. D.
Biochemistry, 2003, 42(34), 10212-10222.
Quantification of Allosteric Influence of Escherichia coli Phosphofructokinase by Frequency Domain Fluorescence
Pham, A.S., Reinharty, G.D.
Biophys. J., 2003, 85, 656-666.
Fluorescence Resonance Energy Transfer Studies on Anthrax Lethal Toxin
Croney, J.C., Cunningham, K.M., Collier, R.J., Jameson, D.M.
FEBS Letters, 2003, 550, 175-178.
DNA Cross-Linking with Metallointercalator-Peptide Conjugates
Copeland, K.D., Lueras, A.M.K., Stemp, E.D.A., Barton, J.K.
Biochemistry, 2002, 41, 12785-12797.
Structural and Biochemical Characterization of a Fluorogenic Rhodamine-Labeled Malarial Protease Substrate
Blackman, M.J., Corrie, J.E., Croney, J.C., Kelly, G., Eccleston, J.F., Jameson, D.M.
Biochemistry, 2002, 41, 12244-12252.
Lateral Diffusion Coefficients in Membranes Measured by Resonance Energy Transfer and a New Algorithm for Diffusion in Two Dimensions
Kuśba, J., Li, L., Gryczynski, I., Piszczek, G., Johnson, M., Lakowicz, J.R.
Biophys. J., 2002, 82, 1358-1372.
Time-Resolved Polarization Imaging By Pump-Probe (Stimulated Emission) Fluorescence Microscopy
Buehler, C., Dong, C.Y., So, P.T.C., French, T., Gratton, E.
Biophys. J., 2000, 79, 536-549.
Cation-Selective Color Sensors Composed of Ionophore-Phospholipid-Polydiacetylene Mixed Vesicles
Kolusheva, S., Shahal, T., Jelinek, R.
J. Am. Chem. Soc., 2000, 122, 776-780.
Low Temperature and Pressure Stability of Picornaviruses: Implications for Virus Uncoating
Oliveira, A.C., Ishimaru, D., Gonçalves, R.B., Smith, T.J., Mason, P., Sá-Carvalho, D., Silva, J.L.
Biophys. J., 1999, 76, 1270-1279.
Water Dynamics in Glycosphingolipid Aggregates Studied by LAURDAN Fluorescence
Bagatolli, L.A., Gratton, E., Fidelio, G.D.
Biophys. J., 1998, 75, 331-341.

Environmental Studies

Hg2+ Reacts with Different Components of the NADPH: Protochlorophyllide Oxidoreductase Macrodomains
Solymosi, K., Lenti, K., Myśliwa-Kurdziel, B., Fidy, J., Strzalka, K., Böddi, B.
Plant Biology, 2004, 6, 358-367.
Real-Time Determination of Picomolar Free Cu(II) in Seawater Using a Fluorescence-Based Fiber Optic Biosensor
Zeng, H.-H., Thompson, R.B., Maliwal, B.P., Fones, G. R., Moffett, J.W., Fierke, C.A.
Anal. Chem., 2003, 75(24), 6807-6812.

Nanomaterials & Nanotechnology

Fabrication and Characterization of Planar Plasmonic Substrates with High Fluorescence Enhancement
Szmacinski, H., Bedugu, R., Lakowicz, J.R..
J. Phys. Chem., 2010, 114(49), 21142-21149.
Coordinatively Induced Length Control and Photoluminescence of W18O49 Nanorods
Woo, K., Hong, J., Ahn, J.-P., Park, J.-K., Kim, K.J.
Inorg. Chem., 2005, 44(20), 7171-7174.
Physicochemical Characterizations of Self-Assembled Nanoparticles of Glycol Chitosan-Deoxycholic Acid Conjugates
Kim, K., Kwon, S., Park, J.H., Chung, H., Jeong, S.Y., Kwon, I.C., Kim, I.-S.
Biomacromolecules, 2005, 6(2), 1154-1158.
Preparation and Characterization of Self-Assembled Nanoparticles of Heparin-Deoxycholic Acid Conjugates
Park, K., Kim, K., Kwon, I.C., Kim, S.K., Lee, S., Lee, D.Y., Byun, Y.
Langmuir, 2004, 20(26), 11726-11731.

Pharmaceutical Chemistry

Thermosensitive Poly(organophosphazene) Hydrogels for a Controlled Drug Delivery
Kang, G.D., Cheon, S.H., Khang, G., Song, S.-C.
European Journal of Pharmaceutics and Biopharmaceutics, in press, Available online 9 March 2006.
Polycations Enhance Emulsion-Mediated in Vitro and in Vivo Transfection
Kim, T.W., Chung, H., Kwon, I.C., Sung, H.C., Shin, B.C., Jeon, S.Y.
International Journal of Pharmaceutics, 2005, 295(1-2), 35-45.

Photochemistry & Photobiology

Fluorescence Lifetimes and Spectral Properties of Protochlorophyllide in Organic Solvents in Relation to the Respective Parameters in Vivo
Mysliwa-Kurdziel, B., Kruk, J., Strzalka, K.
Photochemistry and Photobiology, 2004, 79(1), 62-67.
Nanosecond Photoreduction of Cytochrome P450cam by Channel-Specific Ru-diimine Electron Tunneling Wires
Dunn, A.R., Dmochowski, I. J., Winkler, J. R., Gray, H.B.
J. Am. Chem. Soc., 2003, 125(41), 12450-12456.
PsbS-Dependent Enhancement of Feedback De-Excitation Protects Photosystem II from Photoinhibition
Li, X., Muller-Moule, P., Gilmore, A.M., Niyogi, K.
PNAS, 2002, 99, 15222-15227.

Physical Chemistry

Daunomycin Binding to Detergent Micelles: A Model System for Evaluating the Hydrophobic Contribution to Drug-DNA Interactions
Dignam, J.D., Qu, X., Ren, J., Chaires, J.B.
J. Phys. Chem. B, 2007, 111(39), 11576-11584.
Synthesis, Characterization and Fluorescence Study of Eu(III) Tungstates and Molybdates<
De Farias, R.F, Airoldi, C., Belian, M.F., Alvres, Jr., S.
Journal of Alloys and Compounds, 2006, 419(1-2), 50-53.
Preparative Routes to Luminescent Mixed-Ligand Rhenium(I) Dicarbonyl Complexes
Smithback, J.L., Helms, J.B., Schutte, E., Woessner, S.M., Sullivan, B.P.
Inorg. Chem., 2006, 45(5), 2163-2174.
Detection of Adsorption of Ru(II) and Os(II) Polypyridyl Complexes on Gold and Silver Nanoparticles by Single-Photon Counting Emission Measurements
Glomm, W.R., Moses, S.J., Brennaman, M.K., Papanikolas, J.M., Franzen, S.
J. Phys. Chem. B, 2005, 109(2), 804-810.
Synthesis and Micellar Characteristics of Dendron-PEG Conjugates
Chang, Y., Park, C., Kim, K.T., Kim, C.
Langmuir, 2005, 21(10), 4334-4339.
Nanosecond Photoreduction of Cytochrome P450cam by Channel-Specific Ru-diimine Electron Tunneling Wires
Dunn, A.R., Dmochowski, I.J., Winkler, J.R., Gray, H.B.
J. Am. Chem. Soc., 2003, 125(41), 12450-12456.
Determination of Diffusion Coefficients of Humic Substances by Fluorescence Correlation Spectroscopy: Role of Solution Conditions
Lead, J.R., Starchev, K., Wilkinson, K.J.
Environ. Sci. Technol., 2003, 37(3), 482-487.


Long Wavelength Fluorescence Lifetime Standards for Front-Face Fluorometry
McCranor, B.J., Thompson, R.B.
J. Fluoresc., March 2010, 20(2), 435-440.
Modeling of Spherical Fluorescent Glucose Microsensor Systems: Design of Enzymatic Smart Tattoos
Brown, J.Q., McShane, M.J.
Biosens. Bioelectron., 2006, 21(9), 1760-9.
Coordinatively Induced Length Control and Photoluminescence of W18O49 Nanorods
Woo, K., Hong, J., Ahn, J.-P., Park, J.-K., Kim, K.-J.
Inorg. Chem., 2005, 44(20), 7171-7174.
Fatty Acid Sensor for Low-Cost Lifetime-Assisted Ratiometric Sensing Using a Fluorescent Fatty Acid Binding Protein
Bartolome, A., Bardliving, C., Rao, G., Tolosa, L.
Analytical Biochemistry, 2005, 345(1), 133-139.
[Ru(bpy)2(L)]Cl2: Luminescent Metal Complexes That Bind DNA Base Mismatches
Ruba, E., Hart, J. R., Barton, J. K.
Inorg. Chem., 2004, 43(15), 4570-4578.
Short-Lived Fluorescence Component of DPH Reports on Lipid–Water Interface of Biological Membranes
Konopásek, I., Vecer, J., Strzalka, K., Amler, E.
Chemistry and Physics of Lipids, 2004, 130(2) 135-144.
Reorientational Dynamics of Enzymes Adsorbed on Quartz: A Temperature-Dependent Time-Resolved TIRF Anisotropy Study
Czeslik, C., Royer, C., Hazlett, T., Mantulin, W.
Biophysical Journal, 2003, 84(4), 2533-2541.
Synthesis and Characterization of a Sulfhydryl-Reactive Rhenium Metal-Ligand Complex
Dattelbaum, J.D., Abugo, O.O., Lakowicz, J.R.
Bioconjug. Chem., 2000, 11(4), 533-536.

Accessories available for K2

Sample Compartments

We offer a wide range of Sample Compartments, including one-to-four cuvette holders, an HPCell System and Total Internal Reflection Fluorescence (TIRF) Flow Cell. Learn more >


Learn more about the quality of our UV Glan-Taylor and UV Glan-Thompson Prism Polarizers, and Beam Splitter. Learn more >

Fiber Optics

Learn more about our Chemically Activated Fiber Tip and Fiber Optics, Complete with XY Control and Dichroic Mirror. Learn more >

Microwell Plate Reader

Learn more about our microwell plate reader, capable of using 96- and 384-well plates. Learn more >


We offer a computer-controlled titrators for use with our fluorescence instrumentation product line. Learn more >

Stopped-Flow Apparatus

Our versatile spectrofluorimeters can be interfaced to many stopped-flow apparatuses. Learn more >