Why IFN-γ Remains One of the Most Measured Cytokines in Immunology Research

If you spend any time studying immune responses, you’ll quickly encounter interferon gamma (IFN-γ). It’s one of the most widely measured cytokines in immunology research, and at Millennium Science, it’s also one of the most frequently ordered reagents in our catalogue.

That’s hardly surprising. IFN-γ sits at the centre of many immune processes and is widely used as a functional readout of cellular immune activity. From infectious disease research to cancer immunology and vaccine development, measuring IFN-γ often provides a direct window into how immune cells are responding.

Let’s take a closer look at why this cytokine is so important, and the different ways researchers are measuring it today.

Interferon-γ (IFN-γ) is a type II interferon primarily produced by:

• CD4⁺ Th1 cells
• CD8⁺ cytotoxic T cells
• Natural killer (NK) cells

Unlike type I interferons (such as IFN-α and IFN-β), which are produced by many cell types, IFN-γ is mainly produced by activated immune cells during adaptive and innate immune responses.

Functionally, IFN-γ contributes to several important immune processes:

• Antiviral immunity – enhances immune responses against infected cells
• Immunomodulation – upregulates antigen presentation through increased MHC expression
• Macrophage activation – a key signal driving classical macrophage activation
• Pro-inflammatory signalling – promotes Th1-type immune responses

Because of these roles, IFN-γ is frequently used as a readout of cellular immune activation, particularly when studying T-cell responses.

In many immune assays, IFN-γ acts as a functional marker of antigen-specific immune activity.

Researchers often measure IFN-γ to:

• Evaluate vaccine-induced immune responses
• Assess T-cell immunity to infection
• Study tumour-specific immune responses
• Characterise Th1-biased immune signalling
• Monitor cell therapy potency

This helps explain why IFN-γ assays remain among the most requested cytokine reagents in our portfolio.

Different experiments require different levels of sensitivity, multiplexing, or single-cell resolution. Fortunately, IFN-γ can be detected using several complementary technologies.

1. ELISA – Quantifying Secreted IFN-γ

ELISA remains one of the most widely used cytokine detection methods.

It provides:

• Quantitative measurement of IFN-γ in supernatants, serum, or plasma
• High sensitivity and reproducibility
• A straightforward workflow compatible with most labs

ELISA is ideal when you want to measure total cytokine secretion from a population of cells.

2. ELISpot – Detecting IFN-γ at the Single-Cell Level

ELISpot takes cytokine detection one step further by measuring secretion from individual cells.

This technique enables researchers to:

• Quantify IFN-γ-secreting cells
• Detect rare antigen-specific T cells
• Achieve exceptional sensitivity

Because of this sensitivity, ELISpot has become a widely used approach for T-cell immune monitoring, particularly in vaccine and immunotherapy research.

3. FluoroSpot – Multiplex Cytokine Detection

FluoroSpot expands on ELISpot by allowing simultaneous detection of multiple cytokines using fluorescent detection.

This makes it possible to identify polyfunctional immune cells, which can provide deeper insights into immune responses.

For example, researchers can detect:

• Triple-secreting IFN-γ / IL-2 / TNF-α T cells
• Killer cells secreting IFN-γ and Granzyme B

This type of analysis provides a much richer picture of immune responses, especially when studying complex cell populations.

4. EYRAPlex – Multiplex Cytokine Quantification

For researchers who want high-throughput multiplex cytokine profiling, EYRAPlex assays provide a powerful alternative.

EYRAPlex enables:

• Simultaneous measurement of multiple cytokines
• High-throughput cytokine profiling
• Compatibility with the EYRA instrument platform and most Flow Cytometers

This approach is ideal when researchers want to explore complex cytokine signatures rather than focusing on a single immune marker.

Because IFN-γ remains such a critical immune readout, we’re currently running a limited EOFY promotion.

Until 30 June, you can receive: 10% off Mabtech IFN-γ FluoroSpot assays

If you’re already measuring IFN-γ responses, or planning a new T-cell study, it’s a great opportunity to expand your toolkit.

From infection biology to immunotherapy, IFN-γ remains one of the most informative cytokines to measure when studying cellular immunity.

Whether you’re quantifying cytokine secretion with ELISA, detecting rare antigen-specific cells with ELISpot, studying polyfunctional responses with FluoroSpot, or analysing complex cytokine networks with EYRAPlex, there are now multiple powerful tools available to explore IFN-γ biology.

If you’d like more information about IFN-γ assays or the current EOFY promotion, feel free to reach out.

Until next time… happy experimenting!