Lumit® Insulin Immunoassay

The complete protocol for this product is available in the Technical Manual (#TM776).

How does the Lumit® Insulin Immunoassay work? How does it differ from a traditional ELISA?

The Lumit® Insulin Immunoassay uses a bioluminescent detection principle rather than enzymatic colorimetric detection. Two antibodies, each labeled with a complementary subunit of NanoLuc® Luciferase, bind to insulin in your sample. When both antibodies bind the same insulin molecule, the subunits reconstitute into an active luciferase enzyme, generating a luminescent signal proportional to insulin concentration. Because reconstitution only happens in the presence of analyte, there are no wash steps required. The total assay time is 70 minutes using a standard multimode plate reader, while ELISA measurement of insulin may take hours.

Should I measure cell viability before measuring insulin secretion?

Yes. In metabolic disease research, viability tells you how to read your functional data. The CellTiter-Fluor™ Cell Viability Assay is non-lytic and doesn't utilize ATP, so you can read viable cell number after compound exposure and then run the secretion assay in the same well. Including a viability assay in your workflow distinguishes a compound that impairs beta cell function from one that simply reduces viable cell number. Read viability after treatment; then move to functional readouts like insulin secretion.

What sample types are compatible with the Lumit® Insulin Immunoassay?

The Lumit® Insulin Immunoassay is validated for cell culture supernatants from monolayer cell culture and islet secretion samples. Sample volumes as low as 5µl can be used if reagent amounts are adjusted proportionately (see Table 1 in TM776 for scaling guidance).

What throughput formats does this assay support?

For optimum performance, use opaque, white multiwell plates compatible with your luminometer. The assay can run in either 96-well or 384-well format:

• 96-well format: 50µl sample input, 125µl total reaction volume (W8010 kit: 100 assays; W8012 kit: 500 assays)
• 384-well format: 12.5µl sample input, 31.1µl total reaction volume (W8010 kit: 400 assays; W8012 kit: 2,000 assays)

White plates maximize luminescent signal and minimize well-to-well crosstalk. The assay is flexible for alternative sample volumes ≥5µl provided reagent amounts are adjusted proportionately (see Table 1 in TM776). Any solid white plate compatible with your luminometer should be suitable.

What is the readout for this assay?

The Lumit® Insulin Immunoassay produces a luminescent signal (measured in relative light units, RLU) that is proportional to insulin concentration in your sample. You can analyze raw RLU values or convert them to insulin concentration using a standard curve generated with the supplied insulin standards. Most standard multimode plate readers designed for measuring luminescence are suitable for readout. The assay generates results in approximately 70 minutes from sample addition to final reading, allowing you to move quickly through multiple experimental batches or screening campaigns.

How sensitive is this assay?

The Lumit® Insulin Immunoassay offers picomolar-level sensitivity suitable for cell culture and islet secretion measurements:

• Limit of Detection (LOD): 10pM
• Linear Range: 10pM–8nM
• Signal-to-Background Ratio: >200

Can I measure multiple hormones from the same islet/cell sample?

Yes. Metabolic disease research often requires measuring both insulin (from β cells) and glucagon (from α cells) to understand the full endocrine response. Lumit® Insulin and Lumit® Glucagon Immunoassays are available as separate products. Because the detection principle is the same across both, they can be run in parallel on a perifusion workflow without needing to switch platforms or instruments.

How sensitive does an insulin assay need to be for GLP-1 research?

GLP-1 receptor agonists work by potentiating glucose-stimulated insulin secretion, so your assay needs to detect insulin reliably at the low end of the concentration range typical in cell culture and islet experiments. The Lumit® Insulin Immunoassay has a limit of detection of 10pM and a linear range of 10pM to 8nM, which accommodates the physiological concentration range seen in both monolayer cell cultures and islets. Signal-to-background ratio exceeds 200, which gives you confidence that low-level responses aren’t lost in background noise.