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Technical Support

Our scientists are at the bench daily to produce and validate our antibodies, so they have hands-on experience and knowledge of each antibody’s performance.

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Flow cytometry is sensitive, quantifiable, fast and multiparametric. Large numbers of cells can be analyzed quickly for protein expression, DNA content, cell cycle state, cell size, light scatter characteristics, and ionic shifts—even in very small subpopulations. In addition, modern flow cytometers can measure the intensities of five or more fluorescent markers simultaneously, which is important when the supply of cells is limited. By combining flow cytometry with thoroughly validated antibodies from Cell Signaling Technology, it is possible to examine complex intracellular signaling cascades in cell lines, dissociated tissues, aspirates, or hematology specimens. All of our over 550 antibodies validated for flow cytometry, including our fluorochrome-conjugated antibodies, have been screened to determine optimal dilutions and to verify specificity.

Validation Steps Include

  • Serial dilution is used to determine optimal dilution.
  • Comparison of signal to isotype control is used to estimate the nonspecific binding of primary antibodies.
  • Use of known positive and negative cell lines verifies target specificity.
  • Treatment of cell lines with pathway-specific inhibitors or activators verifies target specificity.
  • The use of blocking peptides, siRNA, and expression vectors verifies specificity of staining.
  • Phosphatase treatment confirms phospho-specificity of the antibody.
  • Extensive quality control testing guarantees stability over time and eliminates lot-to-lot variability.
  • Optimized protocols are provided and dilutions are predetermined.
Titration of BrdU (Bu20a) Mouse mAb #5292.

Flow cytometric analysis of Jurkat cells, unincorporated (red) or after 30 minutes of BrdU incorporation (blue), using serial dilutions of BrdU (Bu20a) Mouse mAb #5292. The fold-induction ratio is shown in green. Optimal concentration of #5292 was determined to be 0.044 µg/ml.

Isotype Control

Isotype Control Example for #3900.

Flow cytometric analysis of SH-SY5Y cells using CREB (D76D11) Rabbit mAb Antibody #4820 (blue) compared to concentration matched #Rabbit (DA1E) mAb IgG XP® Isotype Control #3900 (red).

Activator/Inhibitor Treatment

Activator/Inhibitor Treatment for #9669.

Flow cytometric analysis of Jurkat cells, untreated (blue) or treated with Etoposide #2200 (green), using Cleaved Caspase-3 (Asp175) Antibody (Alexa Fluor® 488 Conjugate) #9669.

Positive/Negative Cell Lines

Positive and Negative Cell Lines for #13355

Flow cytometric analysis of HeLa cells (blue) and HUVEC (green) using CD102/ICAM-2 (D7P2Q) Rabbit mAb #13355. Anti-rabbit IgG (H+L), F(ab')2 Fragment (Alexa Fluor® 647 Conjugate) #4414 was used as a secondary antibody.