Redefine tumor spheroids heterogeneity via PCA-coupled biophysical characterization.

Spheroids, a part of 3D cell culture systems, are crucial models for bridging in-vitro and in-human studies. However, achieving reliable standardization remains difficult, even when comparing spheroids of similar diameters. The challenge arises due to their cross-sectional architecture, which increases heterogeneity and affects biological outcomes. Here we present a novel solution that integrates Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) with Biophysical Characterization (PCA-BC). This approach allows for the identification and classification of variability within and across spheroid populations, offering insights into factors that contribute to heterogeneity. Additionally, it highlights the impact of different operators on spheroid development. The PCA-BC method enables real-time analysis of spheroid samples, facilitating the identification of variability across 3D populations. The integration of PCA and HCA with biophysical characterization provides a clear and efficient means to monitor sample heterogeneity. It also helps track how different operators influence the results, improving overall standardization in 3D cell cultures. By offering structural insights into spheroid heterogeneity, the PCA-BC approach supports more informed decision-making. This significantly improves workflow efficiency, conserving both time and resources, and enhances the reliability of 3D cell culture experiments.