BD LSRFortessa™ X-20

Designed for limited space and boundless potential

The BD LSRFortessa™ X-20 cell analyzer delivers high-performance multicolor analysis with the most compact footprint in its class at just 30" x 29" (76.2 x 73.7 cm) and a height of 30" (76.2 cm).

The analyzer can be configured with up to 5 lasers to detect up to 20 parameters simultaneously to support ever increasing demands in multicolor flow cytometry. A wide range of up to 34 laser choices is available as excitation sources, including blue, red, violet, yellow-green, and UV.

Compact Footprint Optics Fluidics Controls and Analysis Custom Configuration

Flexibility in a Small Space

The BD LSRFortessa™ X-20 fits most flow cytometry analyzer needs, and can be ordered with up to 5 lasers-most commonly, blue, red, violet, yellow-green, and UV-which provides flexibility in laser wavelengths. This allows researchers to optimize assay design by selecting the latest fluorescent dyes and antibodies in experimental protocols. The instrument can accommodate the detection of up to 18 colors simultaneously with a defined set of optical filters that meet today's assay requirements.

The BD LSRFortessa X-20 is designed to support your current assay requirements. In addition, as future needs arise, optical capability can be added or upgraded.

A compact footprint and height of 76.2 x 73.7 x 76.2 cm (30 x 29 x 30 in.) allows the BD LSRFortessa X-20 to fit easily on the benchtop for the cost-effective use of valuable laboratory space. In addition to the reduced size, design enhancements provide easier access to bandpass filters and mirrors, simplifying changes in the instrument configuration.To improve experimental workflow, the optional BD TM High Throughput Sampler (HTS) provides rapid, fully automated sample acquisition from microtiter plates. In high-throughput mode, the HTS option can speed through a 96-well plate in less than 15 minutes with less than 0.5% sample carryover from one well to the next. Low carryover is essential to ensure data quality in research applications.

Maximum Signal, Minimum Crosstalk

The patented collection optics of the BD LSRFortessa™ X-20 are arranged in polygon-shaped optical pathways. Their novel design efficiently maximizes signal detection and increases sensitivity and resolution. This enables researchers to identify cells with especially dim expression, or quantitate rare cell populations, by optimizing multicolor assays and panel design for best results.

Optics system

The optics system uses a novel laser design that illuminates cells in the sample, and collection optics that direct light scatter and fluorescence signals through spectral filters to the detectors. Innovative designs for both the excitation optics and collection optics in the BD LSRFortessa X-20 system minimize light loss and optimize collection efficiency for increased sensitivity and resolution.

Excitation Optics

The excitation optics consist of multiple fixed-wavelength lasers, beam-shaping optics, and individual pinholes which result in spatially separated beam spots.

A final lens focuses the laser light into the gel-coupled cuvette flow cell. Since the optical pathway and the sample core stream are fixed, alignment is constant from day to day and from experiment to experiment.

Optimal resolution of cell populations

Collection Optics

Emitted light from the gel-coupled cuvette is delivered by fiber optics to the detector arrays. The polygonal optical pathways maximize signal detection from each laser-illuminated beam spot. Bandpass (BP) filters in front of each photomultiplier tube (PMT) collect selected fluorophore spectral wavelengths. This arrangement allows filter and mirror changes within the optical array to be made easily without additional alignment.

This design efficiently exploits the principle that light reflection is more efficient than light transmission for fluorescence signal detection. Emitted light travels to each PMT detector via reflection, and is transmitted through only two pieces of glass to reach the detector. Therefore, more colors and higher panel multiplexing can be achieved with minimum light loss.

Superior Performance

While improved laser and optical detection design features have been incorporated into the BD LSRFortessaTM X-20, the fluidics system retains the true fixed-alignment flow cell design. The flow cell is gel-coupled to the collection optics to maximize detector signals.

Fluidics System

The fluidics system is pressure driven. Hydrodynamic focusing forces sample cells through the cuvette flow cell, where they are interrogated. The flow cell is in fixed alignment with the laser and gel-coupled to the collection optics. This design ensures that the laser is precisely focused on the sample stream and the maximum amount of emitted light can be collected for added sensitivity in multicolor applications. Fixed alignment also minimizes startup time, improves experiment-to-experiment reproducibility, and enables automated daily quality control (QC).

The sheath container (8 L) and waste container (10 L) are outside the cytometer, positioned on the floor for easy access.

Fluidics sensors maintain constant pressure, while a fluidics monitoring system warns when sheath fluid is low or empty, or when the waste container is full.

Characterization of instrument sensitivity using 8-peak beads

Greater Consistency

BD FACSDiva™ software controls the efficient setup, acquisition, and analysis of flow cytometry data from the BD LSRFortessa™ X-20 workstation. The software is common across BD FACS™ instrument platforms, including the BD FACSCanto™ cell analyzer and BD FACSAria™ cell sorter systems. This affords researchers greater application flexibility, allowing them to easily move assays from one platform to another.

Cytometer Setup and Tracking

The BDTM Cytometer Setup and Tracking (CS&T) feature of BD FACSDiva software establishes baseline settings and adjusts for instrument variability. The software reduces operator error, and ensures consistency of results by setting the signal time delay across the multiple laser beams and optimizing PMT voltages. Application-specific settings can also be specified, allowing for rapid setup and performance of routine experiments in a more consistent manner. QC tracking capabilities in the software measure instrument settings and report on performance. Levey-Jennings plots help users understand instrument performance and identify maintenance issues.

BD LSRFortessa X-20 front panel

Analysis of human T-cell subsets

Acquisition and Analysis

BD FACSDiva software enables researchers to preview and record data from multiple samples with an automated acquisition process. Acquisition templates, user-defined experiment layouts, and simple compensation procedures are also managed by the software to further facilitate acquisition.

For analysis, the software includes powerful features such as hierarchical snap-to gating, a variety of plot formats, and batch analysis. Recorded data can be analyzed by creating plots, gates, population hierarchies, and statistics views on a BD FACSDiva global worksheet. Once the global worksheet is saved, it can be used to analyze multiple sample tubes from an experiment, thereby saving time.

Numerous other productivity benefits include user-defined batch analysis and automated features such as gate resizing, pausing between data files, exporting statistics, and printing before proceeding to the next data file.

Choices Now and in the Future

The innovative special order program is tailored to meet the special needs of research at the leading edge of biomedical discovery, and offers a wide range of choices to help researchers create the ultimate customized instrument for their requirements.

Multiple Power Options

Cuvette flow cell
Cuvette flow cell

Innovative laser options include the choice of solid state lasers across the full spectrum. Currently, a menu of 18 laser wavelength options is offered, ranging from the complete spectrum of ultraviolet to infrared wavelengths. Through the special order program, researchers can configure a BD LSRFortessa™ X-20 with up to 5 lasers and 20 positional choices for the detectors. In addition to laser wavelength, the special order program offers multiple laser power options and filter selections to better optimize assay needs.

Evolving Capabilities

The BD special order program allows customers to add lasers after their initial system purchase to meet new or evolving requirements. This wide range of choice and flexibility makes the special order BD LSRFortessa X-20 a solid long-term investment.

An Innovation Process

The vigorous sourcing of the latest and best laser technologies ensures an unparalleled range of configuration choices offered by the BD special order program for BD™ LSR cell analyzers. New technologies are regularly incorporated into the product line as soon as they become available.

The ever-expanding list of available lasers demonstrates BD’s ongoing commitment to perpetual innovation. This is one of the many ways BD ensures that the BD LSR cell analyzer platform continues to support the evolving needs of leading researchers around the world.

Image 1: Analysis of human lymphocyte subsets A - E

Image 2: Analysis of human lymphocyte subsets F - J

Instruments Reagents

Optimal resolution of cell populations

Characterization of instrument sensitivity using 8-peak beads

Analysis of human T-cell subsets

Analysis of human lymphocyte subsets A - E

Analysis of human lymphocyte subsets F - J



Data Sheets


Experiment Sheets


Filter Guide


Quick Reference Guides


Technical Specifications




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Class 1 Laser Product.

For Research Use Only. Not for use in diagnostic or therapeutic procedures.

Pacific Blue™ is a trademark and Alexa Fluor® is a registered trademark of Life Technologies Corporation.

CF™ is a trademark of Biotium, Inc.

Cy™ is a trademark of Amersham Biosciences Corp. Cy™ dyes are subject to proprietary rights of Amersham Biosciences Corp and Carnegie Mellon University and are made and sold under license from Amersham Biosciences Corp only for research and in vitro diagnostic use. Any other use requires a commercial sublicense from Amersham Biosciences Corp, 800 Centennial Avenue, Piscataway, NJ 08855-1327, USA.

SPHERO is a trademark of Spherotech, Inc.