Medical & Life Sciences

Cameras for Fluorescence Microscopy OEM

Fluorescence microscopy is a very broadly used term covering numerous applications. This ranges from basic applications in the life sciences to highly developed techniques in which only very few photons or individual molecules are detected and localized by specific high-end hardware and software.

  • Last updated: 14/07/2023

  • Reading time: approx. 4 Minutes

Fluorescence microscopy requires sophisticated cameras
White Paper

CMOS sensors in fluorescence-based applications

In many systems, such as those used for medical, scientific, or clinical diagnostic applications involving fluorescence-based methods, CCD sensors need to be replaced by CMOS sensors. This white paper provides information on selecting a suitable camera and explains the related technical considerations.

To the fluorescence white paper

Why optical format and resolution matter

When you look at the visible wavelength range, the optical setup does not differ significantly from normal light microscopy applications in terms of format, magnification, and resolution. However, the overall cost can increase when larger optical formats, such as F-mounts, are used.

Key optical formats include:

  • C-mounts: Most commonly used, offering high optical performance and a cost-efficient price.

  • S-mounts: Used on instruments with limited sizes and lower cost requirements.

  • Square sensors: Often preferred for capturing the maximum image content.

Camera fluorescence Figure 1. Frontside-illuminated and backside-illuminated pixels
Frontside-illuminated (left) and backside-illuminated pixels (right)

Monochrome or Color

Monochrome cameras are generally preferred for fluorescence applications due to their higher quantum efficiency. The technical factor driving this difference is that in color cameras, Bayer microfilters on each pixel let only certain wavelengths pass through. This filtering is needed to calculate color information of the image using a process called debayering. As the color filters block a certain amount of light, fewer photons reach the photon-reactive area of the pixel. In addition to the Bayer pattern on the sensors, the IR-cut filter in color cameras presents a limiting factor because it blocks light of approximately 650 to 700 nm upward.

Because of red, green, and blue color filters on the pixels, the quantum efficiency is lower in a color camera compared to a monochrome camera. In addition, color cameras typically come with an IR-cut filter blocking light of ~650 to 700 nm upward.
Because of red, green, and blue color filters on the pixels, the quantum efficiency is lower in a color camera compared to a monochrome camera. In addition, color cameras typically come with an IR-cut filter blocking light of ~650 to 700 nm upward.

Typically, images with multiple fluorescence markers for specific detection and co-localization of molecules of interest are made from separate images using monochrome cameras. Selectable light sources and filter sets provide the right combination of excitation and emission wavelengths for each fluorophore used.

However, certain applications may create a demand to do color imaging and fluorescence within one instrument using only one camera. This is possible if the sensitivity demands of the fluorescence application are not too high.

Two fluorescence images of a BPEA cell substrate taken with a front-illuminated IMX174 CMOS sensor in a MED ace 2.3 MP monocamera. The images showing different cell structures are stained and merged by software,.
Two fluorescence images of a BPEA cell substrate taken with a front-illuminated IMX174 CMOS sensor in a MED ace 2.3 MP monocamera. The images showing different cell structures are stained and merged by software,.
Figure 5. Comparison of the noise behavior (with dark current noise) of CCD and CMOS cameras with an exposure time of 4 s. Courtesy of Basler AG.
Comparison of the noise behavior (with dark current noise) of CCD and CMOS cameras with an exposure time of 4 s. Courtesy of Basler AG.

Fluorescence in the Field

Fluorescence is a physical phenomenon and not just a specific technology. The possible methods – e.g. for analytics, quantitative determinations or visualizations used in the life sciences – are almost infinite. Fluorophores can be coupled to various carriers such as proteins (often antibodies), nucleic acids or microparticles. But they can also be integrated as gene technology markers in organisms in order to examine cell-biological functions and processes. Aside from the life sciences, fluorescence-based methods are also used in other areas, such as material analysis or forensics. The following examples show the versatile application options for fluorescence.

How can we support you?

We will be happy to advise you on product selection and find the right solution for your application.

Contact us