Description
STAT3 is a transcription factor activated by cytokine and growth factor signaling, particularly through JAK2 or receptor tyrosine kinases. Once phosphorylated, STAT3 dimerizes and regulates genes governing cell proliferation, survival, and immune responses. Constitutive STAT3 activation is implicated in cancers, such as breast and lung cancers, promoting tumor growth and metastasis, as well as autoimmune and neurodegenerative diseases.
The AlphaLISA SureFire Biotin-Free Human and Mouse Total STAT3 Detection Kit is a sandwich immunoassay for the quantitative detection of total STAT3 in cellular lysates, using Alpha Technology.
Formats:
The HV (high volume) kit contains reagents to run 100 wells in 96-well format, using a 60 μL reaction volume.
The 500-point kit contains enough reagents to run 500 wells in 384-well format, using a 20 μL reaction volume.
The 10,000-point kit contains enough reagents to run 10,000 wells in 384-well format, using a 20 μL reaction volume.
The 50,000-point kit contains enough reagents to run 50,000 wells in 384-well format, using a 20 μL reaction volume.
AlphaLISA SureFire Biotin Free kits are compatible with:
Cell and tissue lysates
Antibody modulators
Biotherapeutic antibodies
Biotin rich samples
AlphaLISA SureFire Biotin Free kits can be used for:
Cellular kinase assays
Receptor activation studies
High-throughput screening for preclinical studies
Total-AlphaLISA SureFire Biotin Free assay principle
The Total-AlphaLISA SureFire Biotin Free assay measures the expression level of a target protein in a biological sample (e.g. cell lysate).
The Total-AlphaLISA SureFire Biotin Free assay uses two antibodies which recognize two different distal epitopes on the target protein. AlphaLISA assays require two bead types: Acceptor and Donor Beads. Acceptor Beads are coated with a proprietary CaptSure™ agent to specifically immobilize the assay specific antibody, labeled with a CaptSure tag. Donor Beads are coated with a proprietary CaptSure3 agent to capture one of the detection antibodies, which is labeled with the CaptSure3 tag. In the presence of target protein, the two antibodies bring the Donor and Acceptor Beads in close proximity whereby the singlet oxygen transfers energy to excite the Acceptor Bead, allowing for the generation of a luminescent Alpha signal. The amount of light emission is directly proportional to the quantity of protein present in the sample.
Total-AlphaLISA SureFire Biotin Free two-plate assay protocol
The two-plate protocol involves culturing and treating the cells in a 96-well plate before lysis, then transferring lysates into a 384-well OptiPlate™ plate before the addition of Total-AlphaLISA SureFire Biotin Free detection reagents. This protocol enables cell viability and confluence to be monitored. In addition, lysates from a single well can be used to measure multiple targets.
Total-AlphaLISA SureFire Biotin Free one-plate assay protocol
Detection of Total target protein with AlphaLISA SureFire Biotin Free reagents can be performed in a single plate used for culturing, treatment, and lysis. No washing steps are required. This HTS designed protocol allows for miniaturization while maintaining robust AlphaLISA SureFire quality.
Activation of Phospho STAT3 (Tyr705) levels in IFNα and IFNγ treated cells
THP-1 cells were seeded in a 96-well plate (50,000 cells/well) in complete RPMI 1640 medium containing 100 nM of PMA for 24 hours at 37°C, 5% CO2. The THP-1 derived macrophages were starved for 2 hours and then treated with increasing concentrations of IFNα or IFNγ for 20 minutes.
After treatment, the cells were lysed with 50 µL of Lysis Buffer for 10 minutes at RT with shaking (350 rpm). STAT3 Phospho (Tyr705) and Total levels were evaluated using respective AlphaLISA SureFire Biotin Free assays. For the detection step, 10 µL of cell lysate (approximately 10,000 cells) were transferred into a 384-well white OptiPlate, followed by 5 µL of Acceptor mix and incubated for 1 hour at RT. Finally, 5 µL of Donor mix was then added to each well and incubated for 1 hour at RT in the dark. The plate was read on an Envision using standard AlphaLISA settings.
As expected, IFNα and IFNγ triggered a dose-dependent increase in the levels of Phospho STAT3 (Tyr705) while Total STAT3 levels remained unchanged.
Validation of Phospho (Tyr705)/Total STAT3 levels in IL-6 treated cells
THP-1 cells were seeded in a 96-well plate (50,000 cells/well) in complete RPMI 1640 medium containing 100 nM of PMA for 24 hours at 37°C, 5% CO2. The THP-1 derived macrophages were starved for 2 hours and then treated with increasing concentrations of IL-6 for 20 minutes.
After treatment, the cells were lysed with 50 µL of Lysis Buffer for 10 minutes at RT with shaking (350 rpm). STAT3 Phospho (Tyr705) and Total levels were evaluated using respective AlphaLISA SureFire Biotin Free assays. For the detection step,10 µL of cell lysate (approximately 10,000 cells) were transferred into a 384-well white OptiPlate, followed by 5 µL of Acceptor mix and incubated for 1 hour at RT. Finally, 5 µL of Donor mix was then added to each well and incubated for 1 hour at RT in the dark. The plate was read on an Envision using standard AlphaLISA settings.
As expected, IL-6 triggered a dose-dependent increase in the levels of Phospho (Tyr705) while Total STAT3 levels remained unchanged.
