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

Fluorescence Imaging Filters

  • Excitation, Emission, and Dichroic Filters for Imaging Applications
  • Matched Filter Sets Designed for Wavelength Ranges of Common Fluorophores

MD568

Dichroic Mirror

MDF-TOM

Filter Set

 

MF630-69

Emission Filter

Arrow Indicates
Direction of Light
Propagation

Etched Corner Indicates Dichroic-Coated Side

Exploded View of a Filter Set Installed Into a Filter Cube

Dichroic
Mirror
Inside Cube

Excitation
Filter

Emission
Filter

Image Plane

Retaining
Ring

Retaining
Ring

Hide Overview

OVERVIEW

Emission Filter

Excitation and emission filters are marked with an arrow that shows the recommended direction of light propagation.

Dichroic Filter

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

Features

  • Excitation, Emission, and Dichroic Filters for Fluorescence Imaging
  • >90% Transmission over Desired Wavelength Band
  • Sharp Cutoff (T < 0.001%) Outside the Transmission Band
  • Matched Filter Sets Designed to Target Many Common Fluorophores
    (See Fluorophores Tab for Alternate Fluorophore Compatibility)
    - BFP
    - CFP
    - WGFP
    - GFP
    - FITC
    - Alexa Fluor® 488
    - YFP
    - tdTomato
    - TRITC
    - TXRED
    - mCherry-A
    - CY3.5
    - mCherry-C


  • 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. They are fabricated at industry-standard dimensions that make them compatible with filter cubes from all major manufacturers. We offer individual filters and filter sets targeted at common fluorophores: BFP, CFP, WGFP, GFP, FITC, Alexa Fluor® 488, YFP, tdTomato, TRITC, TXRED, mCherry-A, CY3.5, and mCherry-C. In addition, the Fluorophores tab provides information on the alternative fluorophores suitable for these filters.

Filter Design
Our filters are manufactured to high-performance optical specifications and designed for durability. They are produced via 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. The resulting hard-coated optics consist of filter layers that are denser than those obtained from electron beam deposition techniques, and which reduce water absorption while greatly enhancing 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.

Each filter is housed in a black anodized aluminum ring which makes handling easier and enhances the blocking OD by limiting scattering. These filters can be mounted in our extensive line of filter mounts and wheels. As the mounts are not threaded, Ø1" retaining rings will be required to mount the filters in one of our internally-threaded SM1 lens tubes.

Filter Cube Mounting Option
For customers who wish to use these filters in Thorlabs, Olympus, or 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(s) at no additional charge. In order to take advantage of this option, please contact Technical Support prior to ordering.


Hide Specs

SPECS

Specification Excitation Filters Emission Filters Dichroic Filters
MDF-GFP2,
MDF-TOM, MDF-MCHC,
& MDF-MCHA Kits
All Other
Excitation Filters
MDF-GFP2,
MDF-TOM, MDF-MCHC,
& MDF-MCHA Kits
All Other
Excitation Filters
MD515, MD568, and Dichroics in
MDF-GFP2, MDF-MCHA, MDF-MCHC,
& MDF-TOM Kits
All Other Dichroics
Size Ø25 +0.0/-0.1 mm Ø25 ± 0.1 mm Ø25 +0.0/-0.1 mm Ø25 ± 0.1 mm 25.2 mm x 35.6 mm 25.0 mm x 36.0 mm
Clear Aperture >Ø21 mm >Ø22 mm >Ø21 mm 80% of Area >(22.5 mm x 32.4 mm)
Angle of Incidence 0° ± 5° 45° ± 1.5°
Thickness 5.0 ± 0.1 mm 3.5 ± 0.1 mm 1.05 ± 0.05 mm 1.0 ± 0.1 mm
Surface Quality 60-40 Scratch-Dig
Substrate Fused Silica
Item # Kit
Item #
Fluorophore Filter
Type
Center
Wavelength
FWHM Reflection
Band
Transmission
Band
AR Coatinga Transmission
Datab
MF390-18 MDF-BFP BFP Excitation 390 nm 18 nm - - - info
MF460-60 Emission 460 nm 60 nm - - - info
MD416 Dichroic - - 360 - 407 nm 425 - 575 nm Rabs < 2%
from 400 to 800 nm
info
MF434-17 MDF-CFP CFP Excitation 434 nm 17 nm - - - info
MF479-40 Emission 479 nm 40 nm - - - info
MD453 Dichroic - - 423 - 445 nm 460 - 610 nm Rabs < 2%
from 400 to 800 nm
info
MF445-45 MDF-WGFP WGFP Excitation 445 nm 45 nm - - - info
MF510-42 Emission 510 nm 42 nm - - - info
MD480 Dichroic - - 415 - 470 nm 490 - 720 nm Rabs < 2%
from 400 - 800 nm
info
MF469-35 MDF-GFP GFP Excitation 469 nm 35 nm - - - info
MF525-39 Emission 525 nm 39 nm - - - info
MD498 Dichroic - - 452 - 490 nm 505 - 800 nm Rabs < 2%
from 400 to 800 nm
info
MF475-35 MDF-FITC FITC Excitation 475 nm 35 nm - - - info
MF530-43 Emission 530 nm 43 nm - - - info
MD499 Dichroic - - 470 - 490 nm 508 - 675 nm Rabs < 2%
from 400 to 800 nm
info
- MDF-GFP2 GFP
Alexa Fluor® 488
Excitation 482 nm 18 nm - - - info
- Emission 520 nm 28 nm - - -
- Dichroic - - 350 - 488 nm 502 - 950 nm -
MF497-16 MDF-YFP YFP Excitation 497 nm 16 nm - - - info
MF535-22 Emission 535 nm 22 nm - - - info
MD515 Dichroic - - 490 - 510 nm 520 - 700 nm - info
- MDF-TOM tdTomato Excitation 531 nm 40 nm - - - info
- Emission 593 nm 40 nm - - -
- Dichroic - - 350 - 555 nm 569 - 950 nm -
MF542-20 MDF-TRITC TRITC Excitation 542 nm 20 nm - - - info
MF620-52c Emission 620 nm 52 nm - - - info
MD568 Dichroic - - 525 - 556 nm 580 - 650 nm - info
MF559-34 MDF-TXRED TXRED Excitation 559 nm 34 nm - - - info
MF630-69 Emission 630 nm 69 nm - - - info
MD588d Dichroic - - 533 - 580 nm 595 - 800 nm Rabs < 2%
from 400 to 800 nm
info
- MDF-MCHC mCherry-C Excitation 562 nm 40 nm - - - info
- Emission 641 nm 75 nm - - -
- Dichroic - - 350 - 585 nm 601 - 950 nm -
MF565-24 MDF-CY3.5 CY3.5 Excitation 565 nm 24 nm - - - info
MF620-52c Emission 620 nm 52 nm - - - info
MD588d Dichroic - - 533 - 580 nm 595 - 800 nm Rabs < 2%
from 400 to 800 nm
info
- MDF-MCHA mCherry-A
Excitation 578 nm 21 nm - - - info
- Emission 641 nm 75 nm - - -
- Dichroic - - 350 - 588 nm 603 - 950 nm -
  • Select dichroics have an AR coating designed for 45° AOI on the back surface. 
  • Click on Emission Filter 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 Tutorial

    TUTORIAL

    Click to Enlarge
    Schematic of light passing through a fluorescence microscope.

    Excitation filter, Emission filter, and dichroic mirror transmission plots
    MDF-YFP filter set transmission graph. Note the dichroic mirror (green) reflects light in the excitation wavelength range (blue), and transmits light in the emission wavelength range (green).

    Filters for Fluorescence Microscopy

    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.

    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, around the peak fluorophore excitation wavelength. For example, as shown in the graph to the right, the bandpass region corresponding to greater than 90% transmission for the Yellow Fluorescent Protein (YFP) Excitation Filter (MF497-16) is 489 - 505 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
    Dichroic mirrors are designed to reflect light whose wavelength is below a specific value (i.e. the cutoff wavelength) while permitting all other wavelengths to pass through it unaltered. In a microscope, the dichroic mirror directs the proper wavelength range to the sample as well as to the image plane. The cutoff wavelength value associated with each mirror indicates the wavelength that corresponds to 50% transmission. For example, as shown in the graph to the right, the cutoff wavelength for the Yellow Fluorescent Protein (YFP) Dichroic Mirror (MD515) is ~515 nm. The Specs tab provides information on wavelength ranges corresponding to ≥ 90% average reflectance and transmission for each type of dichroic mirror.

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

    Although dichroic mirrors play a crucial role in fluorescence microscopy, they are not perfect when it comes to blocking unwanted light; typically, ~90% of the light at wavelengths below the cutoff 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 in addition to the dichroic mirror.

    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, around the peak fluorophore emission wavelength. For example, as shown in the graph to the right, the bandpass region corresponding to greater than 90% transmission for the Yellow Fluorescent Protein (YFP) Emission Filter (MF535-22) is 524 - 546 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 Fluorophore Center Wavelength FWHM
    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.

    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 More Info Icon icons above to view product-specific transmission data. For additional fluorophore compatability, please see the Fluorophores tab.


    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 Excitation 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 Fluorophore Center Wavelength FWHM
    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.

    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 Info Icon icons above to view product-specific transmission data. For additional fluorophore compatability, please see the Fluorophores tab.


    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 Fluorophore Reflection
    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.

    Thorlabs' 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. Each filter is 25.0 mm x 36.0 mm, except for the MD515 and MD568 which are 25.2 mm x 35.6 mm. If your application would benefit from a round, mounted dichroic filter, consider our round Dichroic Filters. Click on the More Info Icon icons above to view product-specific transmission data. For further fluorophore compatability, please see the Fluorophores tab.


    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
    Today
    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 Fluorophore Excitation
    Band
    Emission
    Band
    Dichroic
    (Reflection / Transmission 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-GFP2 info Green Fluorescent Protein (GFP)/
    Alexa Fluor® 488
    482 ± 9 nm 520 ± 14 nm 350 - 488 nm / 502 - 950 nm
    MDF-YFP info Yellow Fluorescent Protein (YFP) 497 ± 8 nm 535 ± 11 nm 490 - 510 nm / 520 - 700 nm
    MDF-TOM info tdTomato 531 ± 20 nm 593 ± 20 nm 350 - 555 nm / 569 - 950 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-MCHC info mCherry-C 562 ± 20 nm 641 ± 37.5 nm 350 - 585 nm / 601 - 950 nm
    MDF-CY3.5 info Cyanine (CY3.5) 565 ± 12 nm 620 ± 26 nm 533 - 580 nm / 595 - 800 nm
    MDF-MCHA info mCherry-A 578 ± 10.5 nm 641 ± 37.5 nm 350 - 588 nm / 603 - 950 nm
    • Click on More Info Icon for a plot and downloadable data.

    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. Dichroic filters have a marking on the side with the beamsplitter coating. Light should be incident on the marked side of the optic for optimal performance. For further fluorophore compatability, please see the Fluorophores tab.


    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-GFP2
    GFP/Alexa Fluor 488 Excitation, Emission, and Dichroic Filters (Set of 3)
    $785.00
    Today
    MDF-YFP
    YFP Excitation, Emission, and Dichroic Filters (Set of 3)
    $625.00
    Today
    MDF-TOM
    tdTomato Excitation, Emission, and Dichroic Filters (Set of 3)
    $785.00
    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-MCHC
    mCherry-C Excitation, Emission, and Dichroic Filters (Set of 3)
    $785.00
    Today
    MDF-CY3.5
    CY3.5 Excitation, Emission, and Dichroic Filters (Set of 3)
    $625.00
    Today
    MDF-MCHA
    mCherry-A Excitation, Emission, and Dichroic Filters (Set of 3)
    $785.00
    Today