Stage-specific embryonic antigen (SSEA)-5 is a pluripotency surface marker expressed in the blastocyst inner cell mass and on human pluripotent stem cells, including both human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs). Because SSEA-5 expression rapidly decreases upon differentiation, it can be used to identify undifferentiated pluripotent stem cells. SSEA-5 can be combined with other pluripotency surface markers (e.g. CD9/CD90 or CD50/CD200) to immunodeplete remaining pluripotent stem cells from incompletely differentiated cultures.
The antibody was conjugated to BD Horizon™ BUV661 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.