MoFlo is a High-Speed Cell Sorter produced by Dako Cytomation (now owned by Beckman Coulter). This particular model, manufactured in 1998, has analogue amplifiers and electronics (big electronic rack in the picture), and with the help of ADC's (Analogue to Digital Converters) is able to transmit data to a computer and where it is processed digitally. MoFlo, which stands for Modular Flow Cytometer, is highly configurable and adaptable to the researcher's needs. Our particular model is equipped with 4 lasers (>7 laser lines) and 9 photo detectors, enabling it to detect up to 9 colors simultaneously. MoFlo is serviced by our own facility, and we have made several modifications described below. Typical fluorescent labels detected are Hoechst, DAPI, CFP, FITC, Alexa488, GFP, CFSE, YFP, PE, PE-TexasRed, PE-Cy5, PI, 7-AAD, PE-Cy7, RFP, mCherry, APC, Cy5, APC-Cy7, etc). Only dedicated staff are allowed to operate the machine, and reservations both for analysis and sorting can be done by sending an email to the facility's staff. For more information, check the following topics:
MoFlo is a jet-in-air system, and consequently sensitivity or excitation efficiency is lower than with cuvette-based flow cells (such as with FACSAria). This negative feature is essentially overcome by using higher power lasers, though some fluorochromes, such as PerCP and its conjugates, are not detected efficiently in this instrument. MoFlo is equipped with 4 different lasers, though only 3 can be used simultaneously. A 200mW Sapphire blue (488nm) laser, a Coherent I 90-4C 4Watt Ar-Ion laser (MLUV and several visible lines), a Spectraphysics 35 mW HeNe red (635nm) laser, and a custom mounted 50mW DPSS yellow (561nm) laser coupled to optics. The number of colors that can be detected by each laser depends on how the instrument is configured. It's therefore difficult to talk about a standard configuration, but we can display a typical configuration for two cases, e.g., when using the UV laser or the yellow laser, together with the other two (see pictures below). The several fluorescent channels are also termed FL1, FL2, etc... although their meaning is quite generic since they depend on how the machine is configured. Note that a band-pass filter designated as 530/40 indicates that it will detect light in the a 40nm range centered at 530nm, i.e., 510-550nm. DLP stands for Dichroic Long Pass filter, and indicates that it will transmit light above the mentioned wavelength and reflect the remaining light below that same wavelength in a given angle (MoFlos dichroics reflect in a 45º angle).
Learning to operate a MoFlo High-Speed Cell Sorter follows a steep curve, requiring a few weeks of dedicated training. For more information and the complete operating procedures for the MoFlo please check "For Flow Operators - Moflo" link.
MoFlo is connected to a PC loaded with Summit Software for machine interface and data acquisition. Data files are saved as FCS files in the computer's hard disk. Files can be transferred to a pen-drive or to one of the xservers following these steps:
IMPORTANT: Remember to check if there is no data loss in your FCS files immediately after transferring the data. We are not responsible for any data loss occuring in MoFlo's workstation.
One of the main advantages the MoFlo is its open architecture allowing the core facility to adapt the instrument to the researcher's needs. It also allows us to implement technical modifications to improve the machine's performance: