Frequently Asked Questions

Yes!  Because of the multiplexing typically employed in flow cytometry, you’ll want to use filters that are fully blocked out-of-band up to about 900nm, which is the detection limit of most PMTs. Typically, almost all of our excitation filters and many of our emission filters will work well in these applications. If you do not see what you need please contact us at sales@chroma.com. We make many other parts that are not yet published on the website. 

We simply need to know the wavelength range that you want the filters to transmit, the wavelength range of the excitation light (typically laser or LED), and the size of the desired filter.

If your system requires dichroic mirrors for an angle other than 45 degrees please contact us, we can provide those as well.

Yes, they are.

Please see our Warranty Information for more details.

No. All of our filter and dichroic designs are very angle-sensitive.  Our emission filters are designed for a zero-degree angle of incidence (AOI) and dichroics are designed for a 45-degree AOI (unless otherwise specified).  Changing this angle will drastically shift the spectral performance of the part.

In most cases, this is not recommended. Our excitation filters are made to block all light from 300-1000nm or higher outside of the bandpass. Most of our emission filters do not block light that far out of the transmission band and therefore might pass some unwanted light from your light source to your sample. More importantly, this unblocked excitation light will then be transmitted to the detector.

In most cases, this is not recommended. Our ET emission filters are made on a different type of glass than excitation filters and ensure image registration between different filter cubes.

Yes, we do recommend an excitation (laser clean-up) filter. Few lasers are truly monochromatic. Gas lasers typically emit several discrete wavelengths and the blocking provided by AOTFs is often insufficient to prevent laser noise in the emission channel. Many laser diodes can have significant bandwidth and should be treated as a broadband source. Also, because laser illumination is very intense, relatively low levels of laser light can dramatically affect the signal/noise ratio of a fluorescence image.

Yes, an excitation filter is required. The output of LED light sources is not monochromatic and instead has a Gaussian-shaped spectral emission profile. The “tails” of this LED emission often extend >40nm from the peak wavelength and must be excluded from the passband of the emission filter. An excitation filter will block these unwanted wavelengths and transmit only the desired wavelengths to your sample.

Yes, the correct dichroic (or polychroic) mirror selection is very important. The job of the dichroic mirror is to reflect the excitation light to the sample and transmit the emission light to the detector.

No, it does not. The price shown with each set includes the filters only. Filter cubes and sliders have their own product numbers. When you order a filter set and cube together we will assemble them for you at no additional cost.

Please see our Filter Cubes and Sliders page for a list of the holders that we carry and their prices.

Please contact the customer service representative, as listed on your order confirmation form or email orders@chroma.com.

Please contact the customer service representative, as listed on your order confirmation form, or email orders@chroma.com. Remember to include the Chroma SO number or your purchase order number along with a description of the changes you need to make. Please also keep in mind that if you placed a credit card order through our website we are limited to the changes that can be made, so we may ask you to resubmit your credit card information depending on the situation.

Please contact the customer service representative, as listed on your order confirmation form or email orders@chroma.com. Please provide the Chroma SO number or your purchase order number when submitting an inquiry.

Your order confirmation will tell you the day your order is scheduled to ship from Chroma. It will also tell you the shipping method we intend to use. Our standard shipping method in the US is two business day service, but overnight service is also available upon request. Orders that are leaving the US are shipped with international priority service, which normally takes 2-3 business days.

Option 1: Search for the part number found on the filter holder. We have hundreds of available spectra to view online. Please note that the spectra you view online may not directly reflect the exact optic you are holding, though it will be very similar.

Option 2: Contact sales@chroma.com and provide the number found directly to the right of the upward-facing arrow on the filter ring, called our lot number. We can use that number to provide the measured spectra for your specific part.

If you are holding a Chroma-mounted filter cube we can usually provide spectra for all the optics contained within, provided it has not been modified. For a cube, set lot numbers are denoted as C-##### and can be found on the side of the filter cube.

Please contact us at returns@chroma.com and tell us which part you need to return. Our normal process is to credit you for returned items and to have you place a new order for the replacement parts. We need to know the original purchase order number or Chroma sales order number (both are found on the sales order confirmation email/fax) and which part you wish to return and why, so we may provide you with an RMA number to send it back. Upon receiving this number, we ask that you fill out our RMA form and follow the instructions provided. You can start the return process by submitting the RMA request.

• Excitation wavelength range to be reflected
• Emission wavelength range to be transmitted
• Application that it will be used for (reflection of excitation and transmission of emission light for epi-fluorescence, emission splitting, TIRF, etc…)
• Size of the optic (if known) or make and model of instrument
• Thickness and flatness requirements if known

These are our catalog filter sets mounted in microscope cubes that have been returned to Chroma for various reasons. These filter sets in cubes have been used minimally or not at all. They are not defective and are inspected and cleaned before being listed on our website. They are substantially discounted and are in excellent condition.

When placing an order, please be prepared to provide ALL of the following items:

• Purchase order number
• Billing address
• Shipping address
• Buyer contact
• Destination contact (if different)
• Item/part number
• Item/part description
• Microscope make and model or part size
• Any special instructions (i.e. mounting changes)
• Quote number if applicable

Having this information on hand will ensure speedy processing and reduce the potential for error.

We want every customer to be happy with their purchase.  Therefore, we have a one-year full satisfaction guarantee on all catalog filters.  If you purchase items that do not work for your application contact us at returns@chroma.com. We help you arrange to return your parts and get you what you need.

For more information, please refer to our Filter Warranty and Return Information pages.

If you are using a purchase order from your company or institution please email this to orders@chroma.com or fax it to 802-428-2525.  If you are placing a credit card order it is best to go to our website here:  https://www.chroma.com/cart .  You can order from a quote online via the chroma.com/cart page and then click the blue button to add items from a quote.  Enter the quote number and email address to which the quote was sent.

We offer a lifetime warranty against manufacturer defects for all catalog sputtered filters, a five-year warranty for catalog metal sputtered filters, and a three-year warranty on other catalog filters. For full details and more information on all parts please visit our Warranty Page.

The first confirmation is an automated acknowledgment of the information submitted on the website. The second is your order confirmation. This is generated after a customer service representative processes your order. This second confirmation contains your customer service representative's name and contact number, your shipping preference, your estimated ship date, and your Chroma Sales Order Number. Please reference this number when making any order inquiries.

Yes. We offer filters to fit all commercial microscopes and home-built systems. Please provide the model of the instrument you will be using to ensure that you receive filters of the correct size. If you are using a home-built system please specify the dimensions of each component of the set including any thickness constraints you may have.