Evaluation of sample stability for cellular kinetics and pharmacodynamic flow cytometry methods.

Area of Science:

• Immunology
• Cellular Biology
• Clinical Chemistry

Background:

• Accurate quantification of cellular kinetics and pharmacodynamic responses is essential for therapeutic monitoring.
• Flow cytometry methods are widely used but sensitive to sample handling and storage conditions.
• Evaluating sample stability is critical for reliable assay development and clinical application.

Purpose of the Study:

• To assess the stability of human whole blood samples for chimeric antigen receptor-T cell enumeration using flow cytometry.
• To determine the stability of basophil activation tests under different storage conditions.
• To compare the performance of conventional EDTA tubes and Cyto-Chex® blood collection tubes for T-cell stability.

Main Methods:

• Comparison of blood collection tubes (EDTA vs. Cyto-Chex®) for chimeric antigen receptor-T cell enumeration.
• Evaluation of sample storage temperatures (room temperature vs. refrigerator) for basophil activation tests.
• Flow cytometry analysis of T-cell counts and basophil activation markers.

Main Results:

• Chimeric antigen receptor-T cells in whole blood were stable for up to 3 days at room temperature in both EDTA and Cyto-Chex® tubes.
• Cyto-Chex® blood collection tubes demonstrated superior consistency compared to conventional EDTA tubes for T-cell enumeration.
• Basophil activation tests remained stable for up to 3 days when stored at refrigerator temperature, but not at room temperature.

Conclusions:

• Sample integrity is crucial for the accurate development of flow cytometry-based cellular kinetics and pharmacodynamic assays.
• Cyto-Chex® blood collection tubes are recommended for improved consistency in chimeric antigen receptor-T cell enumeration.
• Refrigerated storage is necessary for maintaining sample stability in basophil activation tests.