Quantibrite phycoerythrin pe

Deidentified tissue samples were obtained at Stanford University School of Medicine under a protocol approved by the Research Compliance Office at Stanford University. Brain tissue samples at PCWs 20 to 22 were delivered on ice and processed within 3 hours of the procedure. Tissue was processed according to a previously published protocol (89 (link)) to obtain a single-cell suspension. Cells were stained with the following antibodies on ice for 30 min: anti-CD45 (1:25, clone HI30, BioLegend), anti-O4 (1:20, R&D Systems), anti-IGF2R (1:10, BD Biosciences), anti-CD22 (1:20, clone HIB22, BioLegend), anti-MBP (1:100, clone SMI 99, BioLegend), anti-MAP2 (1:20, SMI 52, BioLegend), and human Fc block (1:20, BD Biosciences). After staining, cells were washed, and relevant populations were analyzed on a BD LSRFortessa. Quantibrite–phycoerythrin (PE) (BD Biosciences) beads were resuspended in FACS buffer and analyzed on a BD LSRFortessa. Using the same laser powers and detector voltages, cortical cells and Ramos cells were analyzed for CD22 expression. A standard curve was constructed to correlate PE intensity with number of PE molecules per Quantibrite bead. Last, molecule numbers on human primary cortical brain cell types were calculated by interpolation.