For multicolor flow cytometry of mouse splenocytes, how should CD3/CD4/CD8 antibodies be paired with fluorophores to avoid interference?

The Canto II only has 488/633, so it is recommended to use the most classic three colors: CD3-FITC, CD4-PE, CD8-APC. There is indeed compensation between FITC and PE, but these two channels have strong signals under the 488 laser. After single-stain tubes are set up accurately, compensation is generally within 20%, and Diva automatic compensation can handle it. Do not switch to PerCP-Cy5.5 or APC-Cy7 just to avoid FITC/PE; on this machine, the number of channels and compensation complexity will instead increase. Stain 10^6 cells per tube in a 50 μL system. For antibodies, first perform preliminary experiments according to the manufacturer's recommended amount, and remember to prepare compensation beads or single-stain cells at the same time. If the budget is limited, you can skip isotype controls for now; FMO is more practical.

If the 50-test budget is limited, prioritize ensuring the fluorescence brightness of CD4 and CD8, because these two determine population separation; for CD3, FITC or PerCP can be chosen, but FITC is cheaper and has more clones. Before purchasing, ask the distributor whether trial sizes or small packs are available; sometimes a 5-test or 25-test trial size can be used to first establish the conditions. In addition, under the Canto II 488/633 configuration, APC is usually very stable, so CD8 can be placed in APC to avoid compensation with PE. For splenocytes, CD3/CD4/CD8 staining usually shows clear population separation, so isotype controls are not necessarily required, and reserving an FMO tube is more worthwhile.

A 50-test small pack is generally enough for preliminary experiments, but you need to calculate the number of tubes in advance. A three-color panel requires at least 3 single-stained tubes, 1 blank tube, several FMO tubes, and sample tubes; if each sample is run in triplicate, you may need 12-18 tubes in total. A 50-test pack can cover this at 1 test/tube, but it will be tight if you also need to perform antibody titration. For preliminary experiments, it is recommended to use compensation beads for single-stained tubes or halve the cell number, reduce the staining volume to 50 μL, and reduce the antibody amount proportionally but not below 0.25 μL/tube to avoid excessive error. Buy a larger pack once the formal experiments scale up.