TABLE 1.
Blood stored at −20°C for 6 months using various concentrations of propylene glycol and/or ethylene glycola
| Antifreeze agent | Results with cells (DNA yield) for antifreeze concn (%) ofb:
|
|||||
|---|---|---|---|---|---|---|
| 5 | 10 | 15 | 20 | 25 | 30 | |
| PG | Frozen; total cell lysis (13.6 μg) | Frozen; total cell lysis (14 μg) | Frozen; total cell lysis (9.4 μg) | Frozen; total cell lysis (5.4 μg) | Frozen; total cell lysis (6.4 μg) | Frozen; total cell lysis (8.4 μg) |
| EG | Frozen; total cell lysis (1.76 μg) | Frozen; total cell lysis (2.04 μg) | Erythrocyte lysis; 1–2 leukocytes per field (16.2 μg) | Erythrocyte lysis; 1–2 leukocytes per field (8.76 μg) | Erythrocyte lysis; 1–2 leukocytes per field (8.08 μg) | Erythrocyte lysis; 1–2 leukocytes per field (7.64 μg) |
| E/P | Frozen; total cell lysis (2.88 μg) | Frozen; total cell lysis (8.96 μg) | 300 erythrocytes; 2–3 leukocytes per field (11.96 μg) | 400 erythrocytes; 2–3 leukocytes per field (34 μg) | 300 erythrocytes; 1–2 leukocytes per field (12.04 μg) | 50 erythrocytes; 0–1 leukocytes per field (5.88 μg) |
a
PG, propylene glycol; EG, ethylene glycol; E/P, ethylene glycol and propylene glycol combined in equal parts.
b
DNA yield is the amount of DNA per 400 μl of blood.