RNA-seq Analysis Confirms Post-thaw Transcriptomic Stability in ThawReady™ THP-1 Assay-ready Cells

Cryopreserved cell lines have become essential for high-throughput screening and assay development, offering convenience and consistency across experiments. However, the freeze-thaw process can induce cellular stress, potentially affecting gene expression and compromising functional reliability. To ensure consistent assay performance, it is crucial to verify that cryopreserved cells retain their transcriptomic and functional integrity after thawing. In this study, we evaluated the transcriptomic stability of ThawReady™ THP-1 (ATCC® TIB-202-AR™) cells using RNA sequencing (RNA-seq). Cells were analyzed immediately after thawing (0-hour) and following 2-hour and 8-hour recovery intervals and were compared to freshly cultured THP-1 cells. Principal component and hierarchical clustering analyses revealed that post-thaw samples closely grouped with fresh controls, demonstrating preservation of cellular identity and global gene expression patterns. Gene expression profiles showed strong concordance across key immune and inflammatory pathways characteristic of THP-1 cells. Differential expression analysis identified 178 genes altered at 0 hours, 951 at 2 hours, and 713 at 8 hours post-thaw relative to fresh culture, using a threshold of absolute fold change >5 and FDR-adjusted p-value <0.05. Despite these transient changes, pathways related to cell survival and proliferation remained stable. Notably, phagosome formation was the top-enriched pathway, suggesting adaptive recovery responses that support cell viability. Overall, these results confirm that ThawReady™ THP-1 cells maintain robust transcriptomic integrity post-thaw, supporting their reliability and reproducibility for downstream immune and inflammation-related functional assays.