Microscopy Filter Cubes with Pre-Installed Fluorescence Filters

- Pre-Installed Filters Minimize Handling of Bare Optics
- Drop-In Compatibility with Select Olympus and Nikon Microscopes
- Matched Filter Sets Designed for Wavelength Ranges of Common Fluorophores
TLV-U-MF2-CFP
CFP Filter Cube for Olympus AX, BX2, and IX2 Microscopes
TLV-U-FF-GFP2
Alexa Fluor® 488 Filter Cube for Olympus BX3 and IX3 Microscopes
TLV-TE2000-TOM
tdTomato Filter Cube for Nikon TE2000 and Eclipse Ti

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Quick Links | |
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Fluorophorea | Excitation / Emission Wavelength |
BFP | 390 nm / 460 nm |
CFP | 434 nm / 479 nm |
Wild Type GFP | 445 nm / 510 nm |
GFP | 469 nm / 525 nm |
FITC | 475 nm / 530 nm |
Alexa Fluor® 488 | 482 nm / 520 nm |
YFP | 497 nm / 535 nm |
tdTomato | 531 nm / 593 nm |
TRITC | 542 nm / 620 nm |
Texas Red | 559 nm / 630 nm |
mCherry | 562 nm / 641 nm |
Cyanine (Cy3.5) | 565 nm / 620 nm |
mCherry | 578 nm / 641 nm |

Click to Enlarge
Thorlabs' filter cubes feature labels for identifying installed filters.
Features
- Drop-in Filter Cubes with Pre-Installed Fluorescence Filter Sets for Select Nikon and Olympus Microscopes (See Table Below)
- Filters Optimized for Common Fluorophores (See Table to the Right)
- Pre-Installed Filters Minimize Handling of Bare Optics
- Durable Aluminum Filter Cube Body
- Side Labels for Marking Installed Filters
This page offers Thorlabs' microscope filter cubes with pre-installed fluorescence filter sets. Choose from 13 available imaging filter sets; each is optimized for a specific fluorophore (see table to the right for options) though they may also be used with other fluorophores. Four filter cube body options are available for each filter set; they are compatible with select Olympus and Nikon fluorescence microscopes (see the table below for microscope compatibility).
Thorlabs also sells additional filters and imaging filter sets that are compatible with the cubes sold on this page. For users who already have imaging filter sets, we also provide empty microscope filter cube bodies. Pre-mounted filter cubes using any of our stock filters can be requested by contacting techsupport@thorlabs.com.
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.
Installation of Filters into the TLV-U-MF2 Cube
Microscopy Filter Cubes
These cubes feature a spring plate retention mechanism for the dichroic mirror that results in lower optic stress for improved imaging. Our design also offers an all-aluminum cube body, simplified optic mounting, and three labels for writing information about installed filters. Each cube is also engraved with the empty cube item number. Refer to the table below to view which filter cubes are compatible with which microscope.
Although one filter set is pre-installed into each filter cube, users can easily swap the installed filters. The cubes are compatible with the following filters: one excitation filter (Ø25 mm, up to 5 mm thick), one emission filter (Ø25 mm, up to 3.5 mm thick), and one dichroic mirror (up to 25.2 mm x 36.0 mm x 1.1 mm). Optics can be mounted, aligned, and swapped out easily as illustrated in the video to the right. For detailed assembly instructions, please refer to the assembly manuals in the table below.
When these cubes are placed in a filter cube turret, it is important to balance the weight. To ensure longevity of a motorized filter cube turret and prevent unnecessary wear, please place filter cubes opposing each other to maintain balance.
Microscope Compatibility of Filter Cubesa | |||
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Item # Prefix (Empty Cube Item #) | Microscope Manufacturer | Compatible Microscopes | Assembly Manual |
TLV-U-MF2 | Olympus | AX, BX2, and IX2 Series | TLV-U-MF2 Manual |
TLV-U-FF | Olympus | BX3 and IX3 Series | TLV-U-FF Manual |
TLV-TE2000 | Nikon | TE2000, 50i, 55i, 80i, 90i, Eclipse Ti, and Epi-Fluor Illuminator Scopes | TLV-TE2000 Manual |
Specification | Excitation Filters | Emission Filters | Dichroic Filters | |||
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MDF-GFP2, MDF-TOM, MDF-MCHC, & MDF-MCHA Sets |
All Other Excitation Filters |
MDF-GFP2, MDF-TOM, MDF-MCHC, & MDF-MCHA Sets |
All Other Excitation Filters |
Dichroics in MDF-GFP2, MDF-MCHA, MDF-MCHC, & MDF-TOM Sets |
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 |

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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.
Posted Comments: | |
宇佐川 元久
 (posted 2024-02-08 09:30:56.487) GaN(365nm)の蛍光観察を行いたいと考えており、
365nm以下の波長で励起⇒365nmの波長を観察できる
フィルターキューブを検討しております。
ご対応可能でしょうか? cdolbashian
 (posted 2024-02-19 11:04:48.0) Thank you for reaching out to us with the following inquiry:
"I would like to perform fluorescence observation of GaN (365nm).
Excitation at a wavelength of 365nm or less ⇒ 365nm wavelength can be observed. I'm considering a filter cube. Is that possible?"
Unfortunately, we do not have dichroic mirrors and filters which can be used at this wavelength. |