| Test | Specimen Requirements |
| Zarontin (Ethosuximide)* | 10 mL GEL (white / yellow). Sample Time: Pre-Dose. State time / date of last dose & time / date of collection. |
| Zinc Concentration in:* Serum Urine | 10 mL GEL (white / yellow) or 10 mL LITHIUM HEPARIN (green) 24 hr urine collection in acid washed bottle. |