Thorlabs Inc.
Visit the Fluorescence Imaging Filters page for pricing and availability information

Fluorescence Imaging Filters

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OVERVIEW

Shared Specificationsa
MaterialFused Silica
SizeØ25 mm (Excitation/Emission)
25.2 mm x 35.6 mm (Dichroic)
Thickness5.0 ± 0.1 mm (Excitation)
3.5 ± 0.1 mm (Emission)
1.05 ± 0.05 mm (Dichroic)
Dimensional Tolerance±0.1 mm
Surface Quality60-40 Scratch-Dig
Angle of Incidence0° ± 5° (Excitation/Emission)
45° ± 1.5° (Dichroic)
  • See the Specs tab for additional, product-specific information.

Features

  • Excitation, Emission, and Dichroic Filters for Fluorescence Imaging
  • Provide >90% Transmission at the Desired Wavelength
  • Sharp Cutoff (T < 0.001%) Outside the Transmission Band
  • For Use with 9 Types of Fluorophores (or Their Alternatives)
    • -BFP
      -CFP
      -WGFP
    -GFP
    -FITC
    -YFP
      -TRITC
      -CY3.5
      -TXRED
  • Excitation and Emission Filters are Mounted in Black Anodized Housings
  • Dichroic Filters are Unmounted
  • Filter Sets are Available at a Savings Over Individual Filter Prices

These excitation, emission, and dichroic filters are designed specifically for use in fluorescence imaging applications. The Ø25 mm excitation and emission filters are mounted in black anodized housings that are 5 mm and 3.5 mm thick, respectively, while the 25.2 mm x 35.6 mm dichroic filters are unmounted. Nine types of filters are available to accommodate key wavelength ranges for many common fluorophores (or their alternatives): BFP, CFP, WGFP, GFP, FITC, YFP, TRITC, CY3.5, and TXRED. Please see the Fluorophores tab for information on the alternative compatible fluorophores.

Filter Design
These filters are manufactured to high-performance optical specifications and designed for durability. They are produced with multiple dielectric layers deposited on a high-precision, fused silica substrate. The substrate is ground and polished to ensure that the highest possible image quality is maintained. These hard-coated optics produce filter layers that are denser than those obtained from electron beam deposition techniques. The dense filter layers reduce water absorption and greatly enhance durability, stability, and performance of the filter. Each filter layer is monitored during growth to ensure minimal deviation from design specification thickness, ensuring overall high-quality filter performance. All filters conform to MIL-STD-810F and MIL-C-48497A environmental standards.

Emission Filter

Excitation and emission filters are marked with the recommended direction of light propagation via an arrow on the mount.

Dichroic Filter

Dichroic filters are marked on the side with the dichroic coating. Light should be incident on this side for best performance.

Filter Cube Mounting Option
For customers who wish to use these filters in Olympus and Nikon fluorescence microscopes, Thorlabs manufactures a family of Drop-In Microscope Filter Cubes. If a filter cube is ordered at the same time as one of the imaging filters sold on this page, Thorlabs will premount the filter at no additional charge. In order to take advantage of this option, please contact Technical Support prior to ordering.

Hide Specs

SPECS

SpecificationExcitation
Filters
Emission
Filters
Dichroic
Filters
Substrate MaterialFused Silica
SizeØ25 ± 0.1 mm 25.2 mm x 35.6 mm
Clear Aperture>21 mm80% of Area
Angle of Incidence0° ± 5°45° ± 1.5°
Thickness5.0 ± 0.1 mm3.5 ± 0.1 mm1.05 ± 0.05 mm
Surface Quality60-40 Scratch-Dig
Item #Kit
Item #
FluorophoreFilter
Type
Center
Wavelength
FWHMReflection
Band
Transmission
Band
Transmission
Dataa
MF390-18MDF-BFPBFPExcitation390 nm18 nm--More Info Icon
MF460-60Emission460 nm60 nm--More Info Icon
MD416Dichroic--360 - 407 nm425 - 575 nmMore Info Icon
MF434-17MDF-CFPCFPExcitation434 nm17 nm--More Info Icon
MF479-40Emission479 nm40 nm--More Info Icon
MD453Dichroic--423 - 445 nm460 - 610 nmMore Info Icon
MF445-45MDF-WGFPWGFPExcitation445 nm45 nm--More Info Icon
MF510-42Emission510 nm42 nm--More Info Icon
MD480Dichroic--415 - 470 nm490 - 720 nmMore Info Icon
MF469-35MDF-GFPGFPExcitation469 nm35 nm--More Info Icon
MF525-39Emission525 nm39 nm--More Info Icon
MD498Dichroic--452 - 490 nm505 - 800 nmMore Info Icon
MF475-35MDF-FITCFITCExcitation475 nm35 nm--More Info Icon
MF530-43Emission530 nm43 nm--More Info Icon
MD499Dichroic--470 - 490 nm508 - 675 nmMore Info Icon
MF497-16MDF-YFPYFPExcitation497 nm16 nm--More Info Icon
MF535-22Emission535 nm22 nm--More Info Icon
MD515Dichroic--490 - 510 nm520 - 700 nmMore Info Icon
MF542-20MDF-TRITCTRITCExcitation542 nm20 nm--More Info Icon
MF620-52bEmission620 nm52 nm--More Info Icon
MD568Dichroic--525 - 556 nm580 - 650 nmMore Info Icon
MF565-24MDF-CY3.5CY3.5Excitation565 nm24 nm--More Info Icon
MF620-52bEmission620 nm52 nm--More Info Icon
MD588cDichroic--533 - 580 nm595 - 800 nmMore Info Icon
MF559-34MDF-TXREDTXREDExcitation559 nm34 nm--More Info Icon
MF630-69Emission630 nm69 nm--More Info Icon
MD588cDichroic--533 - 580 nm595 - 800 nmMore Info Icon
  • Click on More Info Icon for a plot and downloadable data.
  • Designed to work with both TRITC and CY3.5.
  • Designed to work with both CY3.5 and TXRED
Hide Transmission Plots

TRANSMISSION PLOTS

The data presented below gives typical transmission values as a function of wavelength and should be used for qualitative comparisons. Small variations may occur from coating run to coating run. These plots should not be used to determine quantitative values of transmission/reflection. Raw data is available by clicking on the info icons info icon   below or by downloading it from the Documents tab above.

Fluorescence Imaging Filters

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TUTORIAL

Filters for Fluorescence Microscopy

Experimental Setup
Transmission vs wavelength for excitation filter

Fluorophores
A fluorophore is a molecule or portion of a molecule that is capable of producing fluorescence. When light of the appropriate frequency necessary to excite a molecule from its ground state to an excited state is present, excitation will occur. However, once in an excited state, the molecule will be unstable. After some short period of time (typically 10-15 to 10-9 s), a photon will be released, thereby enabling the molecule to return to a lower energy state. The emitted radiation will be at a longer wavelength (lower energy) than the absorbed radiation due to the loss of energy through various mechanisms such as vibrations, sound, and thermal energy. 

A single fluorophore can be continually excited unless it is destroyed by photobleaching (i.e. the nonreversible destruction of a fluorophore due to photon-induced chemical damage or covalent modification). The average number of excitation and emission cycles that a particular fluorophore can undergo prior to photobleaching depends on its molecular structure and the local environment; some fluorophores bleach quickly after emitting only a few photons while others are far more robust and can undergo thousands or even millions of cycles before bleaching occurs. Fluorophores used for confocal applications are specifically chosen because they are resistant to photobleaching.

Filters for Fluorescence Microscopy
The experimental setup to the right shows the typical filters used for epi-fluorescence microscopy, a form of microscopy in which both the excitation and emission light travel through the microscope objective. By carefully choosing the appropriate filters and mirrors for a given application, the signal to noise ratio can be maximized. As shown in the schematic to the right, three types of filters are used to maximize the fluorescence signal while minimizing the unwanted radiation. Each optical element is discussed below.

Excitation Filter
The excitation filter only allows a narrow band of wavelengths to pass through it. For example, as shown in the figure to the right, the bandpass region corresponding to greater than 85% transmission for the Green Fluorescent Protein (GFP) Excitation Filter (MF469-35) is 450 – 488 nm; incident radiation outside of this range is either partially (for regions near the transmission region) or totally (for regions further from the bandpass region) blocked by the filter.

Dichroic Mirror
As shown in the experimental setup near the top of this page, the dichroic mirror of a confocal microscope is used to separate the excitation and emission light paths. The transition wavelength value associated with each mirror indicates the wavelength that corresponds to 50% transmission. For example, as shown in the transmission versus wavelength plot below, the transition wavelength for the Green Fluorescent Protein (GFP) Dichroic Mirror (MD498) is ~500 nm.

Dichroic Mirror Transmission versus wavelength plot

Dichroic mirrors are designed to reflect light whose wavelength is below a specific value (i.e. the transition wavelength) while permitting all other wavelengths to pass through it unaltered. The Specs Tab provides information on wavelength ranges corresponding to more than 85% reflectance and transmission for each type of dichroic mirror.

By placing one of these mirrors into the experimental setup at 45o with respect to the incident radiation, the excitation radiation (shown in blue in the experimental setup) is reflected off of the surface of the dichroic mirror and directed towards the specimen and microscope objective, while the fluorescence emanating from the specimen (shown in red in the experimental setup) passes through the mirror to the detection system.

Although the dichroic mirror plays a crucial role in the fluorescence microscope, they are not perfect when it comes to blocking unwanted light; typically, ~90% of the light at wavelengths below the transition wavelength value are reflected and ~90% of the light at wavelengths above this value are transmitted by the dichroic mirror. Hence, some of the excitation light can be transmitted through the dichroic mirror along with the longer wavelength fluorescence emitted by the sample.  To prevent this unwanted light from reaching the detection system, an emission filter is used.

Transmission versus wavelength for emission filter

Emission Filter
An emission filter serves the purpose of allowing the desirable fluorescence from the sample to reach the detector while blocking unwanted traces of excitation light. Like the excitation filter, this filter only allows a narrow band of wavelengths to pass through it. For example, as shown in the figure to the right, the bandpass region corresponding to greater than 85% transmission for the Green Fluorescent Protein (GFP) Emission Filter (MF525-39) is 505 - 545 nm; incident radiation outside of this range is either partially (for regions near the transmission region) or totally (for regions further from the bandpass region) blocked by the filter.

Hide Excitation Filters

Excitation Filters

Item #Transmission
Dataa
Design FluorophorebCenter WavelengthFWHM
MF390-18 Info
Blue Fluorescent Protein (BFP) 390 nm 18 nm
MF434-17 Info
Cyan Fluorescent Protein (CFP) 434 nm 17 nm
MF445-45 Info
Wild Type GFP (WGFP) 445 nm 45 nm
MF469-35 Info
Green Fluorescent Protein (GFP) 469 nm 35 nm
MF475-35 Info
Fluorescein isothiocyanate (FITC) 475 nm 35 nm
MF497-16 Info
Yellow Fluorescent Protein (YFP) 497 nm 16 nm
MF542-20 Info
Tetramethylrhodamine Isothiocyanate (TRITC) 542 nm 20 nm
MF559-34 Info
Texas Red (TXRED) 559 nm 34 nm
MF565-24 Info
Cyanine (CY3.5) 565 nm 24 nm
  • Click on More Info Icon for a plot and downloadable data.
  • Please see the Fluorophores tab for a list of other compatible fluorophores and their absorption and emission spectra.

These excitation fluorescence imaging filters are specifically designed to be used in microscopy and imaging applications. Each Ø25 mm filter is mounted in a 5 mm thick black anodized housing. The housing has an arrow engraved on it that points in the recommended light propagation direction.

These filters provide excellent transmission of the desired excitation wavelength (>90%), with a sharp spectral cutoff and low transmission at other wavelengths (<0.001%). Click on the info icon above to view product-specific transmission data.

Part Number
Description
Price
Availability
MF390-18
BFP Excitation Filter, CWL = 390 nm, BW = 18 nm
$233.00
Today
MF434-17
CFP Excitation Filter, CWL = 434 nm, BW = 17 nm
$233.00
Today
MF445-45
WGFP Excitation Filter, CWL = 445 nm, BW = 45 nm
$233.00
Today
MF469-35
GFP Excitation Filter, CWL = 469 nm, BW = 35 nm
$233.00
Today
MF475-35
FITC Excitation Filter, CWL = 475 nm, BW = 35 nm
$233.00
Today
MF497-16
YFP Excitation Filter, CWL = 497 nm, BW = 16 nm
$233.00
Today
MF542-20
TRITC Excitation Filter, CWL = 542 nm, BW = 20 nm
$233.00
Today
MF559-34
TXRED Exciation Filter, CWL = 559 nm, BW = 34 nm
$233.00
Today
MF565-24
CY3.5 Excitation Filter, CWL = 565 nm, BW = 24 nm
$232.70
Today
Hide Emission Filters

Emission Filters

Item #Transmission
Dataa
Design FluorophorebCenter WavelengthFWHM
MF460-60 Info
Blue Fluorescent Protein (BFP) 460 nm 60 nm
MF479-40 Info
Cyan Fluorescent Protein (CFP) 479 nm 40 nm
MF510-42 Info
Wild Type GFP (WGFP) 510 nm 42 nm
MF525-39 Info
Green Fluorescent Protein (GFP) 525 nm 39 nm
MF530-43 Info
Fluorescein isothiocyanate (FITC) 530 nm 43 nm
MF535-22 Info
Yellow Fluorescent Protein (YFP) 535 nm 22 nm
MF620-52 Info
Tetramethylrhodamine Isothiocyanate/
Cyanine (TRITC/CY3.5)
620 nm 52 nm
MF630-69 Info
Texas Red (TXRED) 630 nm 69 nm
  • Click on More Info Icon for a plot and downloadable data.
  • Please see the Fluorophores tab for a list of other compatible fluorophores and their absorption and emission spectra.

These emission fluorescence imaging filters are specifically designed to be used in microscopy and imaging applications. Each Ø25 mm filter is mounted in a 3.5 mm thick black anodized housing. The housing has an arrow engraved on it that points in the recommended light propagation direction.

These filters provide excellent transmission of the desired emission wavelength (>90%), with a sharp spectral cutoff and low transmission at other wavelengths (<0.001%). Click on the More Information Icon above to view product-specific transmission data.

Part Number
Description
Price
Availability
MF460-60
BFP Emission Filter, CWL = 460 nm, BW = 60 nm
$233.00
Today
MF479-40
CFP Emission Filter, CWL = 479 nm, BW = 40 nm
$233.00
Today
MF510-42
WGFP Emission Filter, CWL = 510 nm, BW = 42 nm
$233.00
Today
MF525-39
GFP Emission Filter CWL = 525 nm, BW = 39 nm
$233.00
Today
MF530-43
FITC Emission Filter, CWL = 530 nm, BW = 43 nm
$233.00
Today
MF535-22
YFP Emission Filter, CWL = 535 nm BW = 22 nm
$233.00
Today
MF620-52
TRITC/CY3.5 Emission Filter, CWL = 620 nm, BW = 52 nm
$233.00
Today
MF630-69
TXRED Emission Filter, CWL = 630 nm, BW = 69 nm
$233.00
Today
Hide Dichroic Filters

Dichroic Filters

Item #Transmission
Dataa
Design FluorophorebReflection
Band
Transmission
Band
MD416 Info
Blue Fluorescent Protein (BFP) 360 - 407 nm 425 - 575 nm
MD453 Info
Cyan Fluorescent Protein (CFP) 423 - 445 nm 460 - 610 nm
MD480 Info
Wild Type GFP (WGFP) 415 - 470 nm 490 - 720 nm
MD498 Info
Green Fluorescent Protein (GFP) 452 - 490 nm 505 - 800 nm
MD499 Info
Fluorescein isothiocyanate (FITC) 470 - 490 nm 508 - 675 nm
MD515 Info
Yellow Fluorescent Protein (YFP) 490 - 510 nm 520 - 700 nm
MD568 Info
Tetramethylrhodamine Isothiocyanate (TRITC) 525 - 556 nm 580 - 650 nm
MD588 Info
Cyanine/Texas Red (CY3.5/TXRED) 533 - 580 nm 595 - 800 nm
  • Click on More Info Icon for a plot and downloadable data.
  • Please see the Fluorophores tab for a list of other compatible fluorophores and their absorption and emission spectra.

Thorlabs' 25.2 x 35.6 mm Dichroic Filters are designed to separate light of different wavelengths. When light is incident on the filter at a 45° angle with respect to the normal, the excitation light and its associated back reflection are reflected while the longer wavelength fluorescence signal is transmitted. These filters are unmounted, but are marked by a dash to indicate the coated side of the filter, which light should be incident on. If your application would benefit from a round, mounted dichroic filter, consider our round Dichroic Filters. Click on the More Information Icon above to view product-specific transmission data.

Part Number
Description
Price
Availability
MD416
BFP Dichroic Filter, Refl. Band = 360-407 nm, Trans. Band = 425-575 nm
$214.13
Today
MD453
CFP Dichroic Filter, Refl. Band = 423-445 nm, Trans. Band = 460-610 nm
$214.13
Today
MD480
WGFP Dichroic Filter, Refl. Band = 415-470 nm, Trans. Band = 490-720 nm
$214.13
Today
MD498
GFP Dichroic Filter, Refl. Band = 452-490 nm, Trans. Band = 505-800 nm
$214.13
Today
MD499
FITC Dichroic Filter, Refl. Band = 470-490 nm, Trans. Band = 508-675 nm
$214.13
Lead Time
MD515
YFP Dichroic Filter, Refl. Band = 490-510 nm, Trans. Band = 520-700 nm
$214.13
Today
MD568
TRITC Dichroic Filter, Refl. Band = 525-556 nm, Trans. Band = 580-650 nm
$214.13
Today
MD588
CY3.5/TXRED Dichroic Filter, Refl. Band = 533-580 nm, Trans. Band = 595-800 nm
$214.13
Today
Hide Filter Sets

Filter Sets

Item #Transmission
Dataa
Design FluorophorebExcitation
Band
Emission
Band
Dichroic
(Refl/Trans Band)
MDF-BFP Info
Blue Fluorescent Protein (BFP) 390 ± 9 nm 460 ± 30 nm 360 - 407 nm / 425 - 475 nm
MDF-CFP Info
Cyan Fluorescent Protein (CFP) 434 ± 8.5 nm 479 ± 20 nm 423 - 445 nm / 460 - 610 nm
MDF-WGFP Info
Wild Type GFP (WGFP) 445 ± 22.5 nm 510 ± 21 nm 415 - 470 nm / 490 - 720 nm
MDF-GFP Info
Green Fluorescent Protein (GFP) 469 ± 17.5 nm 525 ± 19.5 nm 452 - 490 nm / 505 - 800 nm
MDF-FITC Info
Fluorescein isothiocyanate (FITC) 475 ± 17.5 nm 530 ± 21.5 nm 470 - 490 nm / 508 - 675 nm
MDF-YFP Info
Yellow Fluorescent Protein (YFP) 497 ± 8 nm 535 ± 11 nm 490 - 510 nm / 520 - 700 nm
MDF-TRITC Info
Tetramethylrhodamine Isothiocyanate (TRITC) 542 ± 10 nm 620 ± 26 nm 525 - 556 nm / 580 - 650 nm
MDF-TXRED Info
Texas Red (TXRED) 559 ± 17 nm 630 ± 34.5 nm 533 - 580 nm / 595 - 800 nm
MDF-CY3.5 Info
Cyanine (CY3.5) 565 ± 12 nm 620 ± 26 nm 533 - 580 nm / 595 - 800 nm
  • Click on More Info Icon for a plot and downloadable data.
  • Please see the Fluorophores tab for a list of other compatible fluorophores and their absorption and emission spectra.

Since standard fluorescence imaging applications generally incorporate three different filters (i.e., one excitation, one emission, and one dichroic filter) to maximize the signal-to-noise ratio, Thorlabs offers these filters as a set at a savings over purchasing them separately.

Please Note: The excitation and emission filter housings have an arrow engraved on them that points in the recommended direction of light propagation. When using these filters in a setup, light should be incident on this side of the optic in order to achieve optimal performance. Dichroic filters have a marking on their coated side. Light should be incident on this side of the optic for optimal performance.

Part Number
Description
Price
Availability
MDF-BFP
BFP Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-CFP
CFP Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-WGFP
WGFP Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-GFP
GFP Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-FITC
FITC Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-YFP
YFP Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-TRITC
TRITC Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-TXRED
TXRED Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today
MDF-CY3.5
CY3.5 Excitation, Emission, and Dichroic Filters (Set of 3)
$625.00
Today