RG11/39.4 antibody is effective for detection of cell-surface or intracellular Ig by immunofluorescent staining with flow cytometric analysis. FITC-conjugated RG11/39.4 mAb may be used as a primary or secondary reagent in immunofluorescent staining.
Immunofluorescent Staining of Intracellular Immunoglobulin (Ig) Protocol
1. Prepare a single-cell suspension and determine cell number.
2. Suspend cells in staining buffer (PBS + 2% FBS + 0.1% Sodium Azide) at 2 × 10^7 cells/ml and transfer to U-bottom microwell plates in 50 µl/well for immunofluorescent staining.
Note: The BD Pharmingen™ Stain Buffer with FBS (Cat. No. 554656) is effective for use as a staining buffer in this protocol.
3. Block Fcγ receptors by adding 0.2 µg of purified 2.4G2 antibody (Mouse BD Fc Block™ purified anti-mouse CD16/CD32 mAb 2.4G2) (Cat. No. 553141/553142) in 50 µl of staining buffer to each well.
4. Incubate 5 minutes on ice.
5. Add 200 µl of staining buffer/well and resuspend cells. Centrifuge at 250 × g for 5 minutes and aspirate supernatant.
6. Block surface Ig with purified RG11/39.4 mAb (Cat. No. 553889) by adding 1.0 µg per sample in 50 µl of staining buffer/well.
Note: Surface markers may be stained during this step as described in the "Immunofluorescent Staining of Mouse and Rat Leukocytes for Flow Cytometry" in the Technical Protocols section of our web site at
7. Incubate 15 minutes on ice.
8. Wash 2× as described in Step 5.
9. Resuspend cells in 100 µl of BD Cytofix/Cytoperm™ intracellular staining buffer (BD Cytofix/Cytoperm™ Kit, Cat. No. 554714) per well.
10. Incubate 30 minutes at room temperature.
11. Wash 2× with 200 µl of 1× BD Perm/Wash™ buffer (provided in the BD Cytofix/Cytoperm Kit) per well. Centrifuge at 250 × g
for 5 minutes and aspirate supernatant between washes.
12. Stain intracellular Ig by adding ≤ 1 µg of FITC-conjugated RG11/39.4 mAb in 50 µl of 1 × BD Perm/Wash buffer/well.
Note: Other antibodies recommended for staining of intracellular markers may be added during this step as described in Step 12.
13. Incubate for 30 minutes at room temperature.
14. Wash 2× as described in Step 11.
15. Resuspend and transfer samples in 100 µl of staining buffer to tubes appropriate for analysis with a flow cytometer. Bring volume in each tube to 400 µl with staining buffer.
16. Analyze samples on a flow cytometer.