Several on-going studies have begun to reveal significant differences in the stability of allergenic proteins when the extract is prepared with commonly used diluents. Data from our lab indicates that HSA (normal saline with 0.03% human serum albumin) outperforms both normal saline and 50% glycerin over the course of 12 months.
Method
Extracts were diluted in HSA, 50% glycerin, or normal saline and stored at 2-8°C. The major allergen content was then determined at 3, 6 and 12 months using a validated, monoclonal antibody ELISA. Diluent performance is expressed as “percent remaining allergen” for each time point and represented by shaded regions in the chart. Allergens measured in this study include Group 5 grass, Group 1 Bermuda, Birch, Cat, English Plantain, Mugwort/Sage and Olive pollen.
| HSA: |
|
Normal Saline with phenol (0.4%) and 0.03% Human Serum Albumin |
| NSP: |
|
Normal Saline with phenol (0.4%) |
| GLY: |
|
50% glycerin in normal saline with phenol (0.4%) |
| V/V: |
|
Dilution of manufacturer’s concentrate (various dilutions were tested so a dilution range is reported) |
