TABLE 1.
P. falciparum cross-contamination evaluationa
| Sample | Values for each method |
|||||
|---|---|---|---|---|---|---|
| Conventional punch |
Laser cut |
|||||
| CT | Log10 copies (12.0-mm spot) | Parasites/ml | CT | Log10 copies (8.9-mm spot) | Parasites/ml | |
| +++ | 22.49 | 6.76 | 65,173 | 21.85 | 6.95 | 184,330 |
| − | 32.34 | 3.83 | 77 | ND | ND | ND |
| +++ | 21.79 | 6.96 | 105,249 | 21.75 | 6.98 | 197,394 |
| − | 37.81 | 2.20 | 2 | ND | ND | ND |
| +++ | 21.39 | 7.08 | 138,409 | 21.47 | 7.06 | 239,108 |
| − | 37.09 | 2.41 | 3 | ND | ND | ND |
| +++ | 19.98 | 6.96 | 103,338 | 20.10 | 6.92 | 173,978 |
| − | 41.99 | 0.48 | <1 | ND | ND | ND |
| +++ | 19.30 | 7.15 | 163,121 | 20.79 | 6.72 | 109,478 |
| − | 34.55 | 2.71 | 6 | ND | ND | ND |
| +++ | 19.59 | 7.07 | 134,265 | 20.82 | 6.71 | 107,296 |
| − | ND | ND | ND | ND | ND | ND |
| +++ | 19.33 | 7.15 | 159,869 | 20.73 | 6.74 | 113,978 |
| − | 32.73 | 3.24 | 20 | ND | ND | ND |
| +++ | 19.57 | 7.08 | 136,080 | 20.03 | 6.94 | 182,349 |
| − | 36.02 | 2.28 | 2 | ND | ND | ND |
| ++ | 27.18 | 5.36 | 2,627 | 27.5 | 5.27 | 3,850 |
| − | 35.45 | 2.90 | 9 | ND | ND | ND |
| ++ | 26.84 | 5.46 | 3,315 | 27.69 | 5.21 | 3,381 |
| − | 43.66 | ND | <1 | ND | ND | ND |
| ++ | 27.00 | 5.41 | 2,971 | 26.95 | 5.43 | 5,611 |
| − | ND | ND | 0 | ND | ND | ND |
| ++ | 25.36 | 5.39 | 2,791 | 25.89 | 5.23 | 3,568 |
| − | ND | ND | 0 | ND | ND | ND |
| ++ | 24.64 | 5.60 | 4,525 | 26.53 | 5.05 | 2,322 |
| − | ND | ND | 0 | ND | ND | ND |
| ++ | 24.77 | 5.56 | 4,147 | 26.82 | 4.96 | 1,911 |
| − | ND | ND | 0 | ND | ND | ND |
a
Shading denotes cross-contaminated samples based on detection of any 18S rRNA template in the sample. Data were from two experiments using different lots of reagent, a switch which accounts for the shift in threshold cycle (CT) values; assays were recalibrated for each reagent lot. ND, not detected; +++, 4 × 107 parasites/ml; ++, 8 × 103 parasites/ml; −, negative controls.