Shreffler:CFSE Labeling

Overview

Basophil activation in unfractionated samples such as PBMC (note basophils are less dense the Ficoll) or whole blood can be measured by changes in the expression of cell surface markers or even intracellular events (e.g. phosphorylation, oxidative burst, calcium flux) by flow cytometry. Separate markers (e.g. as CD123+ HLA-DR-) are used to specifically identify basophils in addition to those used for assessment of activation.

Materials

• RPMI medium (cellgro, 10-040-CV; store at 4°C in dark)
• 1 X FACS lysing solution (made from 10X stock with dH₂O; store at 4°C; expires in 1 week)
• PBS + 20 mM EDTA (sterile filter, store at 4°C; expires in 1 week)
• Staining Buffer (PBS + 2 mM EDTA + 0.5% BSA) (sterile filter, store at 4°C; aliquot in hood; expires in 2 months)
• desired monoclonal antibodies (e.g. CD63-FITC, CD203c-PE, CD123 PE-Cy5, CD69-APC-Cy7, HLA DR-PE-CY7, CD3-APC, CD14-APC, CD19-APC, CD41a-APC)

Stimulants

May use other antigens for specific application. This will give an idea of the typical dose range we use for antigen-specific responses and controls.

Procedure

1. Suspend PBMCs at 10x10⁶ cells/mL in PBS alone.
2. Ensure that cells are uniformly suspended when CFSE is added.
3. If CFSE negative control is needed, remove cells now.
4. Make '2X' concentration (10 μM) in PBS
   • For example: add 5 mL PBS + 10 μL 5 mM CFSE
5. Combine 1:1 PBMC cells + CFSE (e.g. 5 mL PBMCs + 5 mL CFSE) in 15mL tube and mix completely.
6. Place in 37°C H₂O bath x 10 min.
7. Wash in 10 mL complete medium.
8. Resuspend in medium at desired density

Discussion

discuss this protocol

References

1. Lyons AB and Parish CR. Determination of lymphocyte division by flow cytometry. J Immunol Methods. 1994 May 2;171(1):131-7. DOI:10.1016/0022-1759(94)90236-4 |

Contact

• Who has experience with this protocol?
• Email Wayne Shreffler through OpenWetWare