Table 1.
Depletion of divalent metal ions by Chelex 100 purification of growth media. Chelex chelating ion exchange resin has high preference for copper, iron, zinc, and other divalent heavy metals over monovalent cations such as sodium and potassium with a selectivity for divalent over monovalent ions of approximately 5,000 to 1. To control the efficacy of ion chelation, the Zn concentration of Neurobasal medium was measured by ICP-MS, before and after application of Chelex. Additionally, the growth medium was supplemented with 50 μM ZnCl2 and subsequently subjected to metal depletion. In both cases, Zn levels dropped below the detection limit after purification of the media by Chelex treatment.
| Medium | Average Zn concentration [μmol/L] |
|---|---|
| Neurobasal | 1.42 |
| Neurobasal + Chelex100 | Below detection limit |
| Neurobasal + 50 μM Zn | 44.3 |
| Neurobasal + 50 μM Zn + Chelex100 | Below detection limit |