ELISA Analysis: The Bursa-Yellowlees Method
QuBAS can provide improved accuracy and precision for ELISA analyses
QuBAS is the only bioassay statistics package to implement the Bursa-Yellowlees method, an innovative alternative to traditional ELISA analysis techniques. By making efficient use of every single data point, QuBAS can provide superior accuracy and precision for many ELISA methods.
How does it work?
The Bursa-Yellowlees (BY) method is inspired by relative potency calculations. Assuming we have similarity between a test sample and the standard, we know that any test sample is a dilution of standard. The concentration of the standard is known, meaning we can determine the concentration of the test sample by comparing its response in the assay to that of the reference.
This is precisely what the BY Method does. If a test sample is less concentrated than the standard, then it’s response cure will be shifted to the right relative to the standard curve. Conversely, if the test sample is more concentrated than the standard, then its response curve will be shifted to the left. In both cases, the difference in concentration is encoded into the horizontal shift, which is then used to calculate the overall concentration of the test sample.
Key Advantages
Improved Accuracy and Precision
Traditional ELISA analysis includes only test sample responses within the standard range, leading to arbitrary cut-offs which can reduce precision and introduce potential biases in reportable results. The BY method, by contrast, uses always uses all available responses, providing superior accuracy and precision in many cases. Simulation studies performed by Bursa et al. showed a median confidence interval width of 0.147 using the BY Method versus 0.183 for traditional methods, and an improved accuracy with an average 2.2% bias for the BY Method compared to 2.4% using traditional techniques.
Reduced Assay Failure Rate
By utilising all available response data for every sample, the BY Method extends the range of concentrations for which a valid measurement can be made. This can mean fewer failed samples and fewer retests, leading to massive throughput benefits.
Optimise your Assays
The BY method can provide results which are significantly more precise than those provided by traditional methods, meaning fewer replicates are required to achieve the same precision as using the traditional method with a greater number of replicates. This provides numerous benefits, theamong which is a reduction in the amount of expensive reagents and other materials required for a effective assay. Reducing replication can also mean that more test samples can be included on each plate in some circumstances, which can lead to an improved throughput.