The study of biomarkers associated with human disease and drug responses often requires targeted immunoassays for marker detection and quantitation. There are cases where characterization of a single analyte is sufficient and a conventional ELISA method can be used, but for more complex, multifactorial diseases such as cancers and autoimmune disorders, we ideally want to assess as many potential biological or molecular markers as possible in the same experiment. Why? Because it not only saves time and precious sample volume, but also enables better comparison of pattern shifts in targets associated with changes in biological processes, aiding progression monitoring and outcome prediction.
In these cases, one of the multiplex platforms that BioAgilytix often turns to is the ProteinSimple Ella™, which enables the simultaneous measurement of multiple analytes in a single sample. This technology is particularly beneficial for multiplex biomarker analysis in cases where assay variability and antibody cross-reactivity are of concern because it uses separate parallel channels to detect each analyte.
How the Ella Platform Works
The Ella platform conducts immunoassay testing within a Simple Plex™ cartridge. Samples are run through individual microfluidic channels within the cartridge, each containing three Glass Nano Reactors (GNRs) so that results are produced in triplicate for each sample. The GNRs are coated with a capture antibody that binds the target analyte. The system then automates the steps of washing off unbound analyte, injecting a detection reagent, and removing unbound detection antibody before scanning the GNRs.
Using fluorescence detection, Ella can measure low endogenous levels of proteins across a wider and more sensitive detection range and yield more data points than a traditional plate-based ELISA, since each sample is split into multiple channels and each channel produces three results, one for each GNR.
A Little Volume Goes a Long Way
Perhaps the most valuable aspect of the Ella platform is its ability to deliver consistent, reproducible results with low sample volumes. Oftentimes the reality in our customers’ studies is that volume of samples is limited and/or we are dealing with matrices for which only small samples can be collected. Ella conserves samples while also stretching what we can do with them, using as little as 2.5 µL of sample volume to yield triplicate results per analyte analyzed with a 4-5 log dynamic range. Automation steps also eliminate pipetting error volume discrepancies, mitigating variability to achieve low single-digit CVs.
Supporting Optimal Multiplex Biomarker Assays
There are a number of benefits to multiplex biomarker detection, but this method also inherently creates more complexity and it is important to have the tools in place to reduce potential challenges – one of the most prominent being risk of error from cross-reactivity between the multiple analytes being tested. Ella supports multiplexing without cross-reactivity, enabling our team to uphold excellent assay reproducibility with minimal concern for inaccuracy of results due to immunoassay interference.
As a result, we can deliver more robust identification and characterization of biomarker profiles that can be used to optimize biotherapeutic regimens for patients in need.