Table 3. RD2 results using DNA from formalin-fixed tissues and cultures.
| Case no. | AFB | RD2 from FFPE | RD2 from culture |
|---|---|---|---|
| 30 | +++ | positive | positive |
| 23 | +++ | positive | positive |
| 1 | +++ | positive | positive |
| 3 | +++ | positive | positive |
| 7 | +++ | negative | not donea |
| 9 | +++ | positive | not doneb |
| 10 | +++ | negative | not donec |
| 17 | +++ | negative | Positive |
| 5 | ++ | positive | Positive |
| 2 | + | positive | Positive |
| 4 | + | negative | Positive |
| 12 | + | negative | Positive |
| 15 | + | negative | Positive |
| 16 | + | negative | not donec |
| 18 | + | negative | not donec |
| 29 | + | negative | Positive |
| 6 | + | negative | not donea |
| 8 | + | negative | not donea |
| 13 | + | negative | Positive |
| 19 | + | negative | Positive |
| 20 | + | negative | Positive |
| 21 | + | negative | Positive |
| 22 | + | negative | Positive |
| 24 | + | negative | Positive |
| 26 | + | positive | Positive |
| 27 | + | negative | not donea |
| 28 | + | negative | Positive |
| 31 | + | negative | Positive |
| 25 | + | negative | not donec |
| 11 | none | negative | positive |
| 14 | none | negative | positive |
Comparison of RD2 PCR assay results for FFPE tissues and cultured organisms, showing the relative number of acid-fast bacilli present on lesional FFPE tissues. For cases where RD2 assays were not conducted on cultured organisms, the reason is indicated by a superscript.
AFB = acid-fast bacilli; FFPE = formalin-fixed paraffin embedded tissue
a = no tissue available
b = culture positive but no DNA archived
c = culture negative; + = few AFB (<1/10-20 100X fields); ++ = moderate; AFB present individually or as small clusters in several 40X fields; +++ = large clusters of AFB easily visible at 20X