Options For Light Scatter And New Opportunities For Research

The field of flow cytometry is rapidly maturing, and instrumentation is constantly improving. However, many researchers are frustrated by instrument limitations that make it difficult or impossible to observe small particles that are likely present in samples, yet are undetectable. Fortunately, as manufacturers continue to improve offerings, scientists continue to make new discoveries. During the last decade, investigators have had the means and imagination to explore particles smaller than 1 μm in diameter. While older flow cytometers were limited to detecting particles >500 nm in size, recent instrumentation advancements have improved the detection range to <100 nm, leading to exciting discoveries in cell signaling, tumor metastases, coagulation, inflammation, drug development, disease progression, response to therapeutics, and more. Unfortunately, signals of very small particles are often indistinguishable from background noise caused by instrument operation, buffer composition, sample preparation, sheath particulates, and issues with instrument cleanliness. The Invitrogen™ Bigfoot Spectral Cell Sorter was developed to help scientists overcome these obstacles.

Light scatter design and architecture

Light scatter parameters are essential for robust flow cytometry studies. The Bigfoot Spectral Cell Sorter is equipped with up to 5 highly sensitive light scatter detectors, including forward scatter (FSC) and side scatter (SSC) on the 488 nm laser path, FSC on the 405 nm laser path, and depolarized light scatter detectors for both FSC and SSC on the 488 nm path. All light scatter detectors on the Bigfoot Spectral Cell Sorter are photomultiplier tubes (PMTs) rather than the less sensitive photodiode detectors that are used for FSC detection on many flow cytometers.

This paper characterizes the use of unique light scatter parameters and describes additional features such as below-the-trigger-threshold detection, extremely low background signal, and superior electronics that make the Bigfoot Spectral Cell Sorter well suited for micro- and nanoparticle research.