Table 1. Experiments Conducted to Determine High Abundance Protein (HAP) Stability in Desiccated, Frozen, or Frozen/Thawed Human Serum.
| Experiments Run | Preservation Protocol | Storage Conditions/Time | Methods used for Stability Evaluation ⇒Conclusion |
|---|---|---|---|
| Human Serum (n = 3) | IV* in V1, V2, and V3 (vs. fresh control) | At 22 °C & 0%RH for 1, 3, 7, 16, 18, 20, 22 days | Silver Stain, Western Blot for Albumin and Haptoglobin ⇒ HAP aggregation in dried samples that were sealed |
| Human Serum (n = 3) | IV in V2, V3 vs. freezing at −20 °C or −80 °C (vs. fresh control) | At 22 °C & 0%RH for 1, 3, 7 days | Silver Stain, Western Blot for Albumin and Haptoglobin ⇒ HAP aggregation in dried samples that were sealed, degradation in frozen samples |
| Human Serum (n = 2) | IV in V3 vs. freezing at −20 °C or −80 °C (vs. fresh control) | At 4 °C or 22 °C & 0%RH for 1, 3, 7 days with/without UV exposure | Silver Stain, Western Blot for Albumin and Haptoglobin ⇒ Significant decrease in HAP aggregation ⇒ Liquid sera samples stored in cryogenic conditions have high molecular weight aggregates |
| Human Serum (n = 2) | IV in V2, V3 vs. 4 °C, freezing at −20 °C or −80 °C, 5 Freeze/Thaw to −80 °C (vs. fresh control) | At 4 °C or 22 °C & 0%RH for 1, 2, 4, 6 weeks with/without UV exposure | Silver Stain, Western Blot for Albumin and Haptoglobin ⇒ Frozen state storage causes aggregation/degradation equal to or greater than stabilization matrix ⇒ Significant aggregation during freeze/thaw ⇒ An interesting high molecular weight band which appears predominantly in samples stored at 4 °C |
| Human Serum (n = 3) | IV in V3 vs. freezing at −20 °C or −80 °C, 5 Freeze/Thaw to −80 °C (vs. fresh control) | At 4 °C or 22 °C & 50%RH for 1 week | Silver Stain, Western Blot for Albumin and Haptoglobin ⇒ Degradation in 50%RH samples ⇒ Serum dried w/o lyoprotectant cocktail aggregated the worst |
| Human Serum (n = 3) | IV in V2, V3 vs. freezing at −20 °C or −80 °C | At 4 °C or 22 °C for 2 years with/without UV exposure | Silver Stain, Western Blot for Albumin and Haptoglobin ⇒ Experiments are ongoing |
*Isothermal vitrification (IV) matrices used in experiments:V1: Trehalose + Dextran; V2: Trehalose + Dextran + Tween 20; V3: Trehalose + Dextran + Tween 20 + Glycerol.