AXL is a receptor tyrosine kinase (RTK) in the TAM family, activated by its ligand Growth Arrest-Specific 6 (GAS6). Upon activation, AXL undergoes autophosphorylation, triggering downstream pathways such as PI3K/AKT, MAPK/ERK, and NF-κB, which promote cell survival, proliferation, migration, and immune evasion. In normal physiology, AXL is involved in processes like platelet aggregation, immune regulation, and clearance of apoptotic cells. AXL overexpression or aberrant activation is linked to aggressive cancers, including non-small cell lung cancer (NSCLC), breast cancer, and leukemia, where it contributes to metastasis and drug resistance.
The AlphaLISA SureFire Ultra Human Total AXL Detection Kit is a sandwich immunoassay for the quantitative detection of total AXL 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 Ultra kits are compatible with:
Cell and tissue lysates
Antibody modulators
Biotherapeutic antibodies
AlphaLISA SureFire Ultra kits can be used for:
Cellular kinase assays
Receptor activation studies
High-throughput screening for preclinical studies
Total-AlphaLISA SureFire Ultra assay principle
The Total-AlphaLISA SureFire Ultra assay measures the expression level of a target protein in a biological sample (e.g. cell lysate).
The Total-AlphaLISA SureFire Ultra 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 streptavidin to capture one of the detection antibodies, which is biotinylated. 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 Ultra 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 Ultra 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 Ultra one-plate assay protocol
Detection of Total target protein with AlphaLISA SureFire Ultra 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 Ultra quality.
Validation of AXL Total in cells treated with Gas6 protein
A549 cells were seeded in a 96-well plate (40,000 cells/well) in complete medium and incubated overnight at 37°C, 5% CO2. The cells were treated with increasing concentrations of Gas6 protein for 15 minutes.
After treatment, the cells were lysed with 100 µL of Lysis Buffer for 10 minutes at RT with shaking (350 rpm). AXL Phospho (Tyr702) and Total levels were evaluated using respective AlphaLISA SureFire Ultra assays. For the detection step, 10 µL of cell lysate (approximately 4,000 cells) was 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, the Gas6 protein triggered a dose-dependent increase in the levels of Phospho (Tyr702) AXL while Total levels remained unchanged.
Knockout validation of AXL Total assay
AXL Phospho (Tyr702) levels were assessed in Wild Type (WT) and AXL knockout (KO) A549 cells. AXL KO cells (Abcam ab273744) and WT A549 cells were seeded at various densities in a 96 well plate in complete medium, and incubated overnight at 37°C, 5% CO2.
The cells were lysed with 100µL of Lysis Buffer for 10 minutes at RT with shaking (350 rpm). AXL levels were evaluated by AlphaLISA SureFire Ultra. For the detection step, 10 µL of cell lysate was 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, AXL was detected in WT cells but not in the AXL-KO cell line.
Expression of AXL in various cell lines
Adherent cells were seeded at 40,000 cells/well in a 96-well culture plate in complete medium and incubated overnight at 37°C, 5% CO2. Cells were lysed with 100 µL of Lysis Buffer.
Suspension cells were seeded at 100,000 cells/well in a 96-well culture plate in HBSS + 0.1% BSA, cells were spun down and lysed with 250 µL of Lysis Buffer.
AXL Total levels were evaluated by AlphaLISA SureFire Ultra. For the detection step, 10 µL of cell lysate (approximately 4,000 cells) was 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.
AXL expression is dependent upon cell type. As expected, a very high level of expression was detected in HeLa and A549 cell lines, while signal was low in RT-4 cells.
