What is a filter cube?

Microscope filter cubes are essential components in fluorescence microscopy, designed to optimize the visualization of fluorescent specimens. They house a set of specialized filters that work together to selectively transmit and reflect light at specific wavelengths, allowing researchers to effectively observe and analyze samples.

Key Components of a Microscope Filter Cube

Each filter cube typically contains three main elements:

1. Excitation Filter: This filter transmits only the wavelengths of light that excite the specific fluorochrome used in the sample. It is usually a bandpass filter, allowing a defined range of shorter wavelengths to pass through while blocking others.
2. Dichroic Mirror: Positioned at a 45-degree angle, this mirror reflects the excitation light towards the specimen while allowing the longer-wavelength emission light (fluorescence) to pass through to the detector or eyepiece. The dichroic mirror is crucial for separating excitation from emission light, achieving high efficiency in both reflection and transmission.
3. Emission Filter: Also known as a barrier filter, it is placed after the objective lens and before the detector. This filter allows only the emitted fluorescence to pass through while blocking any remaining excitation light, enhancing the contrast of the observed image.

Matching Filter Cube and Microscope Models

Check the manufacturer's specifications for your microscope model to determine which filter cubes are compatible. Many brands provide compatibility charts on their websites or in product documentation.