Methods for the genetic diagnosis of APL
Cellular level . | Target aberration . | Methods . | Time required, h . | Main advantages . | Main drawbacks . |
|---|---|---|---|---|---|
| Chromosomes | |||||
| t(15;17) | Karyotyping | 16-48 | Highly specific | 24-48 h cultures needed; cryptic fusions undetected (false negatives); need of good quality methaphases | |
| t(15;17) | FISH | 6-24 | No need of dividing cells | No information on the type of PML/RARα fusion | |
| DNA | PML and RARα genes | Southern blot | 96-168 | Highly specific | Time consuming; laborious |
| RNA | PML/RARα fusion | RT-PCR | 4-6 | Rapid; highly sensitive; defines targets for MRD | Poor RNA yield at dx; contamination and artifacts (false positives) |
| Nucleus | Microspeckled nuclear distribution of the PML protein | Immunofluorescence or immunohistochemistry | 2-3 | Rapid; simple; low cost | Artifacts due to cellular degradation, no information on the type of PML/RARα fusion |
Cellular level . | Target aberration . | Methods . | Time required, h . | Main advantages . | Main drawbacks . |
|---|---|---|---|---|---|
| Chromosomes | |||||
| t(15;17) | Karyotyping | 16-48 | Highly specific | 24-48 h cultures needed; cryptic fusions undetected (false negatives); need of good quality methaphases | |
| t(15;17) | FISH | 6-24 | No need of dividing cells | No information on the type of PML/RARα fusion | |
| DNA | PML and RARα genes | Southern blot | 96-168 | Highly specific | Time consuming; laborious |
| RNA | PML/RARα fusion | RT-PCR | 4-6 | Rapid; highly sensitive; defines targets for MRD | Poor RNA yield at dx; contamination and artifacts (false positives) |
| Nucleus | Microspeckled nuclear distribution of the PML protein | Immunofluorescence or immunohistochemistry | 2-3 | Rapid; simple; low cost | Artifacts due to cellular degradation, no information on the type of PML/RARα fusion |
FISH indicates fluorescence in situ hybridization; RT-PCR, reverse transcription-polymerase chain reaction; MRD, minimal residual disease; dx, diagnosis.