CytoFLEX SRT Beckman Coulter cell sorter

Contact: Katarzyna Misztal

Access: with an Operator or training required (1-2 experimental session)


General Description 

CytoFLEX SRT is a fixed alignment benchtop cell sorter. It uses four high-powered lasers: violet (405nm, 80mW), blue (488nm, 50mW), yellow-green (561nm, 30mW) and red (638nm, 100mW). The system is equipped with forward (FSC) and side (SSC) scatter detectors and 15 fluorescence detectors: 

  • Violet 405 (450/50, 525/40, 610/20, 660/10, 780/60)  

  • Blue 488 (525/40, 690/50)  

  • Yellow-green 561 (585/42, 610/20, 675/30, 710/50, 780/60)  

  • Red 638 (610/20, 712/25, 780/60) 

The tube holders for 1.5 ml, 5 ml and 15 ml are provided. There is a multi-well plate sorting module for a variety of plates including 384 format and slides. Index sorting is capable for single-cell applications. CytoFLEX SRT can sort up to four populations simultaneously. The is one 100 µm integrated nozzles available.   

Sample preparation 

  • Prepare cells suspension in filtered buffer (PBS with 2% BSA + 2.5 mM EDTA) but if necessary, in any other medium without phenol red and FCS. 

  • The sample should have particles density of approximately 5-10 million/ml. If less cells are available put, then into minimal volume of 500 µl. 

  • Negative controls and individual positive controls of your staining are required to set sorting gates appropriately. 


  • To improve cells viability, make all preparation steps on ice, unless otherwise stated in your protocol.  

  • To exclude dead cells from the analysis or sorting it is recommended to use DNA-binding dyes as a marker of dead cells.  

  • DNA released from dead cells during cells dissociation causes stickiness. To reduce cells aggregation in your samples, incubate the cells in the presence of DNase I (100 ug/ml with 5 mM MgCl2). 

Further Reading 


  • CytoFLEX SRT Instruction for Use