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- Analytical tools
Rabbit IgG Isotype Control (Alexa Fluor® 647 Conjugate) #3452
Flow cytometric analysis of Jurkat cells, untreated (green) or etoposide-treated (blue), using Phospho-Histone H2A.X (Ser139) (20E3) Rabbit mAb (Alexa Fluor® 647 Conjugate) #9720 compared to Rabbit IgG Isotype Control (Alexa Fluor® 647 Conjugate) (red).Learn more about how we get our images
Flow cytometric analysis of Jurkat cells, untreated (green) or LY294002- and wortmannin-treated (blue), using Phospho-Akt (Ser473) (193H12) Rabbit mAb (Alexa Fluor® 647 Conjugate) #2337 compared to Rabbit IgG Isotype Control (Alexa Fluor® 647 Conjugate) (red).Learn more about how we get our images
Gallery: Rabbit IgG Isotype Control (Alexa Fluor® 647 Conjugate) #3452
Flow Cytometry, Methanol Permeabilization Protocol for Direct Conjugates
A. Solutions and Reagents
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.
- 20X Phosphate Buffered Saline (PBS): (#9808) To prepare 1 L 1X PBS: add 50 ml 20X PBS to 950 ml dH2O, mix.
- 16% Formaldehyde (methanol free).
- 100% methanol.
- Incubation Buffer: Dissolve 0.5 g Bovine Serum Albumin (BSA) (#9998) in 100 ml 1X PBS. Store at 4°C.
NOTE: If using whole blood, lyse red blood cells and wash by centrifugation prior to fixation.
- Collect cells by centrifugation and aspirate supernatant.
- Resuspend cells in 0.5-1 ml 1X PBS. Add formaldehyde to obtain a final concentration of 4%.
- Fix for 15 min at room temperature.
- Wash by centrifugation with excess 1X PBS. Discard supernatant in appropriate waste container. Resuspend cells in 0.5-1 ml 1X PBS.
- Permeabilize cells by adding ice-cold 100% methanol slowly to pre-chilled cells, while gently vortexing, to a final concentration of 90% methanol.
- Incubate 30 min on ice.
- Proceed with immunostaining (Section D) or store cells at -20°C in 90% methanol.
- Aliquot desired number of cells into tubes or wells.
- Wash cells by centrifugation in excess 1X PBS to remove methanol. Discard supernatant in appropriate waste container. Repeat if necessary.
- Resuspend cells in 100 µl of diluted antibody conjugate (prepared in incubation buffer at the recommended dilution).
- Incubate for 1 hr at room temperature. Protect from light.
- Wash by centrifugation in incubation buffer. Discard supernatant. Repeat.
- Resuspend cells in 1X PBS and analyze on flow cytometer; alternatively, for DNA staining, proceed to optional DNA stain (Section E).
E. Optional DNA Dye
- Resuspend cells in 0.5 ml of DNA dye (e.g. Propidium Iodide (PI)/RNase Staining Solution #4087).
- Incubate for at least 5 min at room temperature.
- Analyze cells in DNA staining solution on flow cytometer.
posted July 2009
revised June 2017
Note: This control antibody must be diluted to the same concentration (not dilution) as the specific antibody in analysis. See Directions on Use.
Important Note on Use: This control antibody must be diluted to the same concentration (not dilution) as the specific antibody in analysis. Higher background fluorescence may result if excessive amounts of rabbit IgG isotype control are used. Do not use this antibody at 1:50 dilution in the same way as recommended for other CST Alexa Fluor® conjugated antibodies.Storage: Supplied in PBS (pH 7.2), less than 0.1% sodium azide and 2 mg/ml BSA. Store at 4°C. Do not aliquot the antibody. Protect from light. Do not freeze.
The purified antibody is not directed against any known antigen. It functions as an isotype control for rabbit antibodies.
The antibody was isolated from naive rabbit sera and purified by affinity chromotography. The antibody was conjugated to Alexa Fluor® 647 under optimal conditions with a F/P ratio of 2-6.
Rabbit IgG was conjugated to Alexa Fluor® 647 fluorescent dye under optimal conditions, and tested in-house for direct flow cytometric analysis of human and mouse cells. Alexa Fluor® dye is maximally excited by red light (e.g. 633 nm He-Ne laser). Antibody conjugated of the Alexa Fluor® 647 dye produce far-red-fluorescence emission with a peak at 655 nm.
Isotype control antibodies are used to estimate the nonspecific binding of target primary antibodies due to Fc receptor binding or other protein-protein interactions. An isotype control antibody should have the same immunoglobulin type and be used at the same concentration as the test antibody.
For Research Use Only. Not For Use In Diagnostic Procedures. Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc. The Alexa Fluor dye antibody conjugates in this product are sold under license from Life Technologies Corporation for research use only, except for use in combination with DNA microarrays. The Alexa Fluor® dyes (except for Alexa Fluor® 430 dye) are covered by pending and issued patents. Alexa Fluor® is a registered trademark of Molecular Probes, Inc.