Why should the cut-off depth of the fluorescent filters group be above OD5?

We all know that fluorescent filters are one of the important detection methods in the biomedical field. Fluorescent filter groups are key optical components for excitation selection and fluorescence extraction, and corresponding filter spectra need to be designed based on the excitation and emission characteristics of the selected reagents. Generally, we require the background depth of the filter to be at least OD5 (optical density, abbreviated as optical density) in order to achieve good fluorescence imaging results.

In recent years, with the continuous emergence of biomedical detection technologies such as fluorescence probe technology, fluorescence microscopy, polarized fluorescence detection technology, multi-photon fluorescence detection technology, PCR gene amplification and quantitative detection, higher technical requirements have been put forward for the steepness and background depth of fluorescence filters.


The duration of stimulated emission fluorescence of fluorescent reagent is very short: the emitted fluorescence brightness is equivalent to the magnitude of one thousandth to one thousandth of the excitation energy. Compared with the excitation, the fluorescence is very weak, and both coexist in the test sample; And the wavelength gap between the excitation spectrum and emission spectrum of fluorescence is very small At around 15nm-30nm, in order to detect fluorescence signals, we need to deeply isolate the excitation light and emission light in the fluorescence system from each other in the spectrum. The isolation degree must reach above OD4 to detect the fluorescence signal emitted by the sample. To improve the accuracy of fluorescence detection, the isolation degree needs to be increased to above OD5. Moreover, the higher the isolation degree of the filter, the stronger the detection ability of trace fluorescence, and the higher the detection accuracy of the fluorescence microscope.

So the core requirements of filters in fluorescence microscopes are high cutoff steepness, high transmittance of filters, and filter neighborhood background cutoff

At present, HANZHONG BORISUN OPTICS can achieve a cutoff depth of OD6 on a single 1.0mm thick filter. We welcome more customers to call and inquire.


Hanzhong Brisun Optics Co., Ltd. Is the high precision optical element manufacturer provides customized production of Various optical lenses, including spherical lens, cylindrical lens, optical window, mirror, prism, filter, metal base mirror and other high-precision optical elements. The base materials include various optical glass, fused quartz, calcium fluoride (CaF2), zinc selenide (ZnSe), germanium (GE), silicon (SI), sapphire, metal and other materials. And provide antireflective film, high reflection film, spectroscopic film, metal film and other optical coatings.

Welcome to OEM and Purchasing!

Recent Posts
Send Requests
Contact Form Demo (#3)