Table 5. Method characteristics of dideoxy-sequencing, DxS-KRAS and KRAS-TMGB in diagnostic KRAS mutation assessment (KRAS codons 12 and 13).
| sequencing | DxS (IVD test) | TMGB | |
| efficiency | |||
| relatively well preserved DNA | high | high | high |
| very fragmented DNA | usually non-informative | high | very high |
| accuracy | |||
| relatively well preserved DNA | golden standard?* | high | high |
| very fragmented DNA | usually non-informative | high | high |
| selectivity | |||
| relatively well preserved DNA | 25–30% | ≤1%& | <1% |
| very fragmented DNA | n.a. | usually>10% | usually>10% |
| method process | |||
| method simplicity | complex, multi-step | one-step | one-step |
| PCR product transfer & handling | required | none | none |
| time-to-result, post DNA-extraction | days | 2 hrs | 2 hrs |
| sample re-processing required | quite oftenˆ | seldom | seldom |
| lab experience | |||
| technical skills required for application | high expertise | basic expertise (PCR) | basic expertise (PCR) |
| controls | golden standard | provided | sequencing validation required |
| cut-offs | subjective evaluation | provided | assessment in the lab |
| cost/DNA sample# | X (sense & antisense) | 10X + controls | 1,8X + controls |
* = results may not be accurate in cases with tumor cell content below the selectivity of this method, even in samples with preserved DNA
& = reported by the manufacturer
ˆ = failure to obtain results necessitates troubleshooting at each of the multiple steps of this method; DNA extraction had also to be repeated in some cases
# = one successful assessment is meant; cost compared to sequencing with analogies according to reagent prices in Greece