For many sites, Cyto-Chex® has become the go-to solution due to its simplicity: a single-step blood draw directly into the tube. However, Cyto-Chex is known to preserve immune cell populations for up to two weeks before cell population and functional marker loss occurs. This creates a tradeoff: ease of use versus long-term integrity.
In our latest study, we evaluated whether Cyto-Chex is compatible with downstream TokuKit processing by directly comparing two workflows:
- Gold standard workflow (Direct-to-TokuKit): Blood collected into Sodium Heparin (NaHep) then processed into TokuKit for long-term storage and analysis.
- Clinical trial workflow (Cyto-Chex-to-TokuKit): Blood collected directly into Cyto-Chex, held for 48 hours at room temperature (to mimic shipping), then processed into TokuKit.
Experiment design:
- Blood collected from 3 healthy donors
- Each donor contributed 2 mL samples across four conditions
- NaHep 2h → TokuKit → -80C
- Cyto-Chex 2h → TokuKit → -80C
- NaHep 48h → TokuKit → -80C
- Cyto-Chex 48h → TokuKit → -80C
- All samples were thawed, processed and analyzed on the same day using a 25-marker spectral flow cytometry panel (Cytek Aurora) to assess both immune cell population frequencies and functional marker expression
Key finding:
At 48 hours, Cyto-Chex-to-TokuKit preserved immune cell frequencies comparable to the Direct-to-TokuKit workflow, demonstrating that CytoChex does not negatively impact TokuKit preservation. Additionally, rare populations such as plasmablasts were preserved better with Cyto-Chex-to- + TokuKit in comparison to a NaHep tube left at room temperature for 48 hours, indicating that this workflow has the ability to preserve rare/fragile cell populations.
We believe this workflow has the potential to transform immune monitoring in clinical trials. By combining Cyto-Chex with TokuKit, sites can retain operational simplicity while gaining access to long-term blood sample preservation.
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