Isolating multiple populations at once saves time and makes efficient use of sample. Whether sorting one subpopulation or six, the BD Influx sorter can be quickly configured to best fit researchers’ application requirements. A wide range of standard collection options supports two-, four-, and six-way sorting. Tube holders include sizes from microtubes, to 12 x 75-mm tubes, to 15-mL tubes.
The BD Influx system uses parallel electronics to reach a throughput rate of 200,000 events per second, independent of the number of parameters. For high sensitivity and low noise, the BD Influx system uses analog electronics in the first stage of signal amplification. The output of the analog peak and hold circuitry is digitized using 16-bit ADCs and placed on a patented parallel processing digital bus. The bus handles real-time compensation as well as other digitized signals, including area and width of up to eight additional pulses. To sort cells, researchers can select subpopulations through the creation of up to 32 sort regions. A variety of sort modes, optimized to favor purity, yield, or count accuracy, is standard. A custom mode allows researchers to optimize those settings for a specific application.
If purity is of no concern, theoretically sort speed is as fast as the throughput rate. In this case, cells are sorted independently and the target population is enriched.
In most sorts, however, purity is a major concern, and factors such as droplet formation rate, event rate, and sample quality play a deciding role. When these factors are taken into account, the yield can be calculated by using Poisson’s statistics. The BD Influx system will reach >80% of Poisson’s expected yield with properly prepared samples.
Accudrop technology simplifies drop-delay determination
BD FACS Accudrop technology simplifies setup and eliminates manual calculations normally required. Accurately calculating the drop-delay determination—the point at which the drop separates from the stream—is important because it ensures that the instrument precisely places the charge on the drop containing the particle of interest.
Accudrop technology assists the researcher to set the optimal drop-delay value. The drop-delay value can be adjusted while viewing BD FACS™ Accudrop beads, which are illuminated in the center and side sort streams. The researcher can identify the precise drop-delay value without a fluorescence microscope or manual calculations.
The BD Influx system can adapt to virtually any environment. A small footprint allows the instrument to fit into tight spaces, and a modular component design allows the instrument to be easily configured to specific needs. Footprint and modularity have made the BD Influx cell sorter the instrument of choice for marine biology applications. The BD Influx Mariner version includes pre-amp modifications for dimly fluorescent microorganisms and a brace to secure fluidics tanks for shipboard installation.
A range of standard detection modules is available to configure the system based on application needs.
Optional, exchangeable detector modules provide the capability to measure small particles, the polarization state of scatter, or fluorescence signals. This flexibility allows the user to adapt the system to the needs of routine or emerging applications.
Small Particle Option
Small Particle Option with polarization
The BD Influx system can be equipped with polarization-sensitive detectors. A unique polarization design uses two detectors mounted under Brewster angles to measure changes in parallel and perpendicular light for both scatter or fluorescence. Changes in polarization can help differentiate between organisms containing highly reflective inclusions such as diatoms, or discriminate among different populations of granulocytes.
Small Particle Option
The Small Particle Option on the BD Influx system improves forward scatter detection. This option lowers the threshold on size measurements using a special detector with a high NA microscope lens, a pinhole, and a photomultiplier tube (PMT). The pinhole reduces the amount of stray light reaching the detector and prevents saturation of the PMT. Optimized sheath fluid (0.1-micron filtered) lowers the intrinsic noise level, which enables measurement of particles as small as 200 nm.
This resolution makes the Small Particle Option particularly valuable for applications in marine biology, microbiology, and environmental biology. The Small Particle Option also allows researchers to detect fluorescence in the forward direction. This capability is used in applications such as chlorophyll detection.
Computerized Cell Deposition Unit
For precise sorting, the mechanics and speed of the XY table in the Computerized Cell Deposition Unit (CCDU) allow sorting into microtiter plates or other custom devices such as slides or petri dishes. Single-cell cloning or sorting for single-cell PCR or single-cell imaging techniques is possible with the standard CCDU.
Make exploratory cloning more efficient with index sorting
Index sorting functionality has been completely rewritten and extended to put a very powerful analytical technique in the hands of researchers. It is now possible to review the complete flow phenotype of every cell sorted into a multiposition sort device, such as a 96-well tray. Index sort mode creates an FCS file containing all the sort deposition information and tray position information on an event-by-event basis. Each sorted event in the file is “indexed” one-by-one according to the X and Y coordinates of the sort collection device. Post-sorting results can be precisely traced back to the flow characteristics of the specific cell or combinations of cells sorted.
In addition to sorting into tubes, the BD Influx sorter supports an endless variety of slides, plates, and custom devices. Predefined trays and slides include 384-, 96-, 24-, and 6-well plates, coarse and fine calibration slides, and 4 x 12 slides.