Getting Started with Measuring Cellular Metabolism

You might have noticed shifts in metabolic activity in your experiments—something like patterns emerging from RNA-seq, proteomics, or imaging that hint at deeper changes in how your cells generate and use energy. Measuring metabolites like glucose or lactate gives you a window into key metabolic pathways. Unlike static molecular snapshots, metabolite assays allow you to quantify dynamic, functional changes over time.

Whether you're phenotyping a new cell line, evaluating a drug treatment, or exploring a disease model, these measurements reveal underlying metabolic activity and cellular function where metabolites often serve as biomarkers, correlating with specific phenotypes or treatment responses. With the right experimental setup, you can track metabolite increases or decreases across conditions and generate meaningful, quantitative data.

We have developed ready-to-use bioluminescent assays — no specialized equipment or extensive training is required. If you have access to a standard luminometer, your lab is set up to run these assays. Our assays have a simple add-incubate-read workflow, easy to integrate even if your lab is new to measuring metabolism. These assays are also highly versatile: they are compatible with cells in suspension or adhered to a surface, organoids, tissue homogenates, serum or plasma, and more. In many cases, you can collect meaningful data directly from the culture media —saving your cells for downstream applications like RNA-seq or proteomics.

For details on how the assays work, visit our metabolism guide.

While our luminescent metabolite assays cover a broad range of needs, they’re not the only tool available for metabolite detection. If you're interested in spatial resolution or want to visualize metabolic activity subcellularly, imaging methods may be a better fit. For real-time oxygen consumption data, a Seahorse analyzer is your best bet. And if you need a comprehensive profile of all metabolites in a biological system, consider mass spec- or NMR-based metabolomics. Our luminescent assays are a great starting point, but not a one-size-fits-all solution.

A well-designed experiment is essential for generating both informative and reproducible results. Start by thinking through your controls and media conditions by considering the following:

Appropriate controls

• A positive control or standard is included in most kits to verify assay performance.
• A negative control is a sample not expected to produce assay signal (e.g., untreated cells), and helps confirm assay specificity.
• A background control (media or buffer only) quantitates baseline signal in your samples.

Media composition

• Metabolites present in standard culture media can elevate your background levels. Consider using low-nutrient formulations where appropriate to detection changes.
• If performing intracellular readouts, always wash cells thoroughly with PBS to remove extracellular metabolites from the media that can interfere with your results.

While our cellular energy metabolism assays are highly flexible and compatible with various sample types, sample prep is critical. A few simple steps will help ensure accurate, reproducible results across conditions and replicates.

Treat all samples with acid and base prior to analyzing.

This step is recommended for most assays because it inactivates endogenous enzymes, helping to eliminate unwanted enzymatic activity that could degrade target metabolites, increase background, or interfere with luminescence. Many kits include the necessary acid/base components, but some do not and you will need to prepare them yourself. If acid/base treatments are performed, no additional pre-treatment steps are needed before assaying samples. However, you should always consult individual kit instructions to determine if exceptions apply.

Optimize sample concentration.

Start by ensuring that metabolite levels fall within the linear range of the standard curve. Different cell types produce varying levels of metabolites, so you may need to adjust cell number or tissue input accordingly. If your samples contain high levels of the target metabolite, a dilution step may be necessary, and optimizing the dilution factor can help bring concentrations into the linear range. Keep in mind that intracellular metabolite levels are often much lower than extracellular levels. If you're unsure what concentration to expect, consulting the literature can provide helpful reference points.

Consider timing for secretion or uptake experiments.

Shorter incubation times can help capture early or subtle changes in secreted metabolite levels, while longer timepoints may be required to detect accumulation or depletion. The optimal incubation duration will depend on the specific metabolite, its expected rate of change, and the biological dynamics of your system.