Table 19.1.2.
Time Considerations
| Procedure | Quantity | Time |
|---|---|---|
| Collecting and counting cercariae | From 200 snails | 1.5–2 hr |
| Exposing mammals to cercariae | 30 mice or 10 hamsters | 1.5–2 hr |
| Preparation of in vitro schistosomules | From 2 × 105 cercariae | 2–2.5 hr |
| Collection of lung schistosomules | From 10 mice | 4 hr |
| Collection of adult worms | From 15 mice, 2 hamsters | 1 hr |
| Counting eggs in tissues (including overnight incubation) | From 10 mice | 24 hr |
| Isolating eggs for injection or antigen preparation | From 20 livers | 4 hr |
| Preparation of crude SEA | From 2 × 106 eggs | 2 hr |
| Rearing newly hatched snails to exposable size (5–8 mm diameter [B. glabrata]; 2–3 mm length [Bulinus spp.]; 4–6 mm in length [O. hupensis ssp.]) | Indeterminate | 1–2 months (depending on species, water temperature) |
| Exposing snails to miracidia | 500 snails | 2–3 hr |
| Cryopreserving schistosomules | 20,000 cercariae | 4–5 hr |
| Thawing cryopreserved schistosmules for injection into mice | <20,000 schistosomules | < 1 hr |