TABLE 1.
Percent recovery of quantitative immunofluorescent microscopy for enumeration of Giardia cysts in runoff water samples
| Stormwater turbidity (NTU)a | No. of cysts added per 500 ml runoff waterb | Mean no. (range) of cysts detectedc | Mean % recovery (range) |
|---|---|---|---|
| 1 | 10 | 2 (1-3) | 20 (10-30) |
| 50 | 11 (9-12) | 22 (18-24) | |
| 200 | 55 (28-108) | 27 (14-54) | |
| 100 | 10 | 0 | 0 |
| 50 | 0.3 (0-1) | 50 (0-200) | |
| 500 | 2 (1-3) | 43 (20-72) | |
| 500 | 50 | 0 | 0 |
| 500 | 0.3 (0-1) | 20 (0-80) | |
| 1,500 | 2.5 (2-3) | 57 (40-80) | |
| 700 | 50 | 0 | 0 |
| 500 | 0.3 (0-1) | 40 (0-160) | |
| 1,500 | 0.5 (0-1) | 23 (0-53) |
a
NTU, nephelometric turbidity units.
b
Four replicates per dose.
c
Number of Giardia cysts present in a 10-μl smear.