Investigations if death is inevitable and a metabolic cause is suspected
| Specimen | Sampling details |
| Plasma | 3–5 ml lithium heparin sample, plasma separated and frozen |
| Whole blood for DNA analysis | 3–5 ml EDTA sample kept refrigerated (should not be frozen) (other whole blood samples can also be used) |
| Blood spot for acylcarnitine analysis | 2–3 spots on filter paper or Guthrie card |
| Urine | Frozen in a plain sterile container |
| Skin biopsy for fibroblast culture | Collected using aseptic technique, stored in a skin biopsy medium (if this is not available, viral culture medium or normal saline in a sterile container may be used) (should not be frozen) |
| Muscle biopsy | 1 cm3 piece immediately frozen in liquid nitrogen or dry ice for enzymology, histology, and DNA analysis; one piece preserved in gluteraldehyde for electron microscopy |
| Liver biopsy | 1 cm3 piece immediately frozen in liquid nitrogen or dry ice for enzymology, histology, and DNA analysis; one piece preserved in gluteraldehyde for electron microscopy |