# Comparative Analysis of Manual ELISA and Ella, an Automated Instrument for ELISA, in Measuring Serum Galectin-3 Levels in Breast Cancer Patient Samples

## TL;DR

This study compares manual and automated methods for measuring galectin-3 in breast cancer patients, finding that the automated method is more precise but gives lower readings.

## Contribution

The study provides a direct comparison of manual ELISA and the Ella instrument for galectin-3 measurement in breast cancer patients, highlighting their differences in precision and accuracy.

## Key findings

- Ella measurements of serum galectin-3 are significantly lower than manual ELISA measurements.
- Ella shows higher precision with lower coefficient of variation compared to manual ELISA.
- The difference between methods remains consistent across breast cancer stages and histologies.

## Abstract

Galectin-3 is a protein involved in the immune system that may be useful for future breast cancer treatments. Serum galectin-3 levels are usually measured using manual Enzyme-Linked Immunosorbent Assay (ELISA), but new automated tools, such as the Ella instrument, can perform ELISA more quickly and reliably. The goal of this paper is to see whether there is a difference in the measurements of serum galectin-3 between the manual ELISA and the new Ella instrument. Serum galectin-3 levels were measured in 95 breast cancer patients using both manual ELISA and automated Ella. Our study found that there is moderately good agreement between ELISA and Ella measurements, but Ella measurements tend to be lower than those of manual ELISA. The Ella instrument was also more precise, resulting in less variation in measurements of the same sample. This study helps clarify the differences between ELISA and Ella, which should be taken into consideration for measuring galectin-3 levels in breast cancer patient samples.

Background: Circulating galectin-3 (Gal-3) levels have been indicated as a promising diagnostic, prognostic, and therapeutic target in breast cancer patients. Specifically, serum galectin-3 levels are traditionally measured using manual Enzyme-Linked Immunosorbent Assay (ELISA), but recent automated methods, such as Simple Plex assay by ProteinSimple™ run on an Ella instrument, have shown promising evidence of being more efficient and less error-prone than manual methods. This paper aims to assess whether there are differences in serum galectin-3 measurements between manual and automated ELISA methods. Methods: Serum galectin-3 levels were initially analyzed from one hundred and fifteen breast cancer samples using both manual ELISA and the Ella instrument. Following coefficient of variation (CV) and outlier analysis, ninety-five samples were analyzed further with JMP statistical software to perform Shapiro-Wilk, Spearman’s correlation, Wilcoxon signed-rank, and regression analyses. Results: The Ella instrument resulted in significantly lower CV values, confirming that it is more precise and reliable than manual ELISA methods. There was a moderate correlation between ELISA and Ella measurements (r = 0.49, p < 0.0001), but a Wilcoxon signed-rank test revealed that serum gaelectin-3 measurements obtained with the Ella instrument were significantly lower compared to those obtained with manual ELISA, with a mean difference of −5.19 ng/mL (p < 0.0001). Regression analysis showed a significant increase in the difference between manual ELISA and Ella measurements as serum galectin-3 levels increase (p < 0.0001). This difference in measurements between manual and automated ELISA techniques remained consistent when analyses were performed within each breast cancer stage, immunophenotype, and histology. Conclusions: While the Ella instrument is a fast and reliable tool, the discrepancies between manual ELISA and the Ella instrument in quantifying serum galectin-3 levels are important to consider prior to widespread use.