Comparative Analysis of Manual ELISA and Ella, an Automated Instrument for ELISA, in Measuring Serum 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.