Swapping RIA for ELISA Without Losing Data

For over two decades, a field research team studying marmots relied on radioimmunoassay (RIA) to measure fecal glucocorticoid metabolites. It wasn’t fancy, but it was reliable – exactly what long-term field studies demand. 

And when you’re tracking stress hormones in wild populations year after year, reliability beats novelty every time. 

But eventually, the drawbacks of RIA began to mount. Managing radioactive materials, navigating outdated disposal regulations, and facing supply chain issues for isotopes – all of it added friction to a project already running on tight schedules and tighter budgets. 

So, they did what many labs are considering: they started testing ELISA kits. 

The goal wasn’t just to ditch the radioactivity. It was to find an ELISA that could hold up next to their validated RIA method without compromising data quality. Same samples. Same extraction. Same expectations. 

So how do you switch from RIA to ELISA kits?

Simple, the two kits went head-to-head: one from Cayman Chemical, the other from Arbor Assays. 

Only one matched the established RIA data closely enough to maintain the integrity of the long-term dataset: Arbor Assays’ DetectX® Corticosterone Multi-Format ELISA Kit. 

Why It Worked 

The Arbor kit delivered where it counted: 

• Wide dynamic range 
  • The team saw accurate readings at both low and high hormone concentrations. The Cayman kit topped out, masking meaningful variation in animals with elevated stress levels. 

• Seamless integration with existing methods 
  • The researchers used their same fecal extraction process without needing new buffers or adjustments. It just worked. 

• Tighter data, less noise 
  • With better inter- and intra-assay precision, the Arbor kit delivered more consistent results across replicates. 

• Continuity with confidence 
  • This wasn’t just about convenience. This was about protecting the scientific value of 20 years of data as research methods evolved. 

What It Means for Your Lab 

If your team still relies on RIAs to measure stress hormones like corticosterone, it may be time to revisit your options.  Today’s ELISA technologies offer the sensitivity, specificity, and consistency needed to support long-term studies without disrupting your baseline datasets. 

The Arbor Assays corticosterone kit is validated for multiple sample types, including feces, plasma, serum, saliva, urine, and hair. That flexibility is especially important when working across species or shifting matrices. 

This isn’t about abandoning previous methods. It’s about strengthening continuity with tools that match today’s research demands. 
 

From Marmots to Methods That Work 

In the end, the shift from RIA to ELISA wasn’t just a technical upgrade for the marmot research team. It was a practical decision grounded in the need for reliable, long-term data. Their study depended on consistent stress hormone measurements across years and individuals, and the Arbor Assays ELISA kit delivered. 

By validating the ELISA against their original RIA data, they ensured continuity without compromising scientific integrity. That move gave them the confidence to expand hormone tracking across species, sample types, and seasons, without losing sight of what brought them to the mountains in the first place. 

Ready to Move on from RIA? 

Check out Arbor Assays’ Corticosterone Multi-Format ELISA Kit or browse the full lineup of stress hormone kits. Built for researchers who prioritize continuity, precision, and performance.