Exploring Protein Detection Techniques in Biodistribution Studies of mRNA Therapeutics/Vaccines

Welcome to SoCal Biosciences’ latest newsletter! This month, we’re diving into some of the most essential protein detection methods used in biodistribution studies for mRNA treatments. As mRNA-based treatments expand into new areas, including vaccines, cancer therapies, and rare disease interventions, they bring us closer to targeted, effective treatments. These therapies instruct cells to produce therapeutic proteins directly, tackling diseases by addressing root causes. But ensuring these treatments work as intended means understanding where these therapeutic proteins end up in the body—and that’s where biodistribution studies come into play.

Biodistribution studies help us understand the journey of mRNA therapeutics/vaccines post-administration. They show us not only if the mRNA therapeutics/vaccines reach the right tissues but also if they stay there long enough to be effective and avoid non-target areas to reduce potential side effects. Using sophisticated detection methods like Enzyme-Linked Immunosorbent Assay (ELISA), Meso Scale Discovery (MSD), Mass Spectrometry (MS), and Western Blotting, researchers can gather high-quality data on the distribution and localization of these proteins, supporting safer and more efficient mRNA treatments.

ELISA has been a mainstay in protein quantification since the 1970s, when Peter Perlmann and Eva Engvall developed it as a non-radioactive alternative for measuring protein levels. With a system of enzyme-linked antibodies that detect specific proteins, ELISA is a sensitive and adaptable tool that’s especially useful for high-throughput biodistribution studies.

The versatility of ELISA is a major part of its appeal. Here’s how its main formats work:

Using enzymes such as horseradish peroxidase (HRP) or alkaline phosphatase (AP), ELISA creates a signal proportional to the protein amount, providing a quantitative readout that can be measured by spectrophotometry.

ELISA has kept pace with evolving research needs, including new high-throughput and multiplex versions. Microfluidic and bead-based ELISAs enable simultaneous detection of multiple proteins in a single sample, ideal when working with small tissue volumes, which are common in biodistribution studies.

ELISA’s reliability and sensitivity make it perfect for tracking therapeutic proteins in tissues. By providing quantitative data on protein levels over time, ELISA helps researchers determine how effectively a treatment is reaching and acting in target tissues.

Introduced in the early 2000s, Meso Scale Discovery (MSD) combines electrochemiluminescence with multiplex immunoassays, allowing researchers to quantify multiple proteins simultaneously with exceptional sensitivity. Its use of ruthenium-based tags provides a stable signal with minimal interference, which is critical in complex biodistribution samples.

In biodistribution studies, MSD shines when researchers need to analyze multiple markers simultaneously. This is especially helpful in understanding therapeutic protein distribution, immune responses, and interactions in various tissues.

Mass Spectrometry (MS) has come a long way since its origins in early 20th-century physics. It became viable for protein analysis in the 1980s with advancements like Matrix-Assisted Laser Desorption Ionization (MALDI) and Electrospray Ionization (ESI). MS’s sensitivity and ability to analyze complex protein mixtures make it ideal for biodistribution studies, allowing researchers to profile therapeutic proteins with high specificity.

MS is indispensable for biodistribution studies needing detailed protein profiles, from therapeutic to off-target proteins. By providing both identification and quantification, MS reveals a full picture of a treatment’s biological effects.

Western blotting, established in 1979, remains a fundamental technique for confirming protein size and integrity. Using gel electrophoresis to separate proteins by size and antibodies for detection, Western blotting is essential for validating the identity of proteins detected in biodistribution studies.

Western blotting offers size-based confirmation of protein identity, which is crucial in verifying therapeutic protein detection from quantitative assays.

In biodistribution studies, Western blotting serves as a confirmatory method, validating results from quantitative methods like ELISA, MSD, or MS. By confirming the detected protein’s identity, Western blotting provides an additional layer of assurance in biodistribution data.

Each method we’ve explored offers unique strengths, and together, they give researchers a comprehensive view of protein expression in biodistribution studies:

Combining these techniques enables biodistribution studies to provide precise, in-depth insights into mRNA therapeutic/vaccine behavior across the body, supporting the development of safer, more effective RNA treatments.

Thank you for joining us for this edition on protein detection in biodistribution studies! In our next issue, we’ll be diving into lipid detection methods—a vital component in understanding mRNA therapeutic delivery. Stay tuned!