In the field of oncology in particular, targeted therapies are used because at molecular levels tumours differ from one another. This calls for a corresponding therapy in each case.
The authoritative bodies link the use of therapeutic antibodies – aimed at the growth receptor EGFR of tumour cells – with a molecular-diagnostic test. It is only when relevant tumour genes (KRAS, BRAF, EGFR, PI3K) have not mutated that a treatment is likely to be successful.
Cube Dx tests used in mutation analysis provide sensitive results which are specific for each individual mutation of clinical relevance. This means that the efficiency level is of prime importance: minimal manual activity and a concept by means of which the cost of processing even an individual sample is proportionally the same as for processing multiple samples.
A small amount of sample (upwards of 15 ng) of genomic DNA from tumour-affected tissue is adequate and prepared with a reaction mixture for PCR.
The DNA segment in which the target mutations appear is amplified by the PCR. The individual strands are labelled with a fluorescent dyestuff.
The amplified product is pipetted into the hybcell which is transferred to the fully-automatic processing device hyborg. Several samples can be prepared and processed at the same time.
The real analytical procedure commences with a click on the start button.
The amplified DNA binds with immobilised primers on the surface of the hybcell. In the case of a perfect match these primers are lengthened by a highly-specific polymerase. Subsequently, the marked amplified products remain bound to the lengthened primers even at a high temperature. Any amplified product which has not increased in length is dissolved in the course of a stringent washing step.
The measured values are interpreted by the software and displayed in tabular form in a report covering the measurement range. They are expressed as the proportion of mutant to non-mutant (mt) DNA (%).
The tests use DNA extracted from (tumour-) tissue. Normally (FFPE-) tissue fixed with formalin and embedded in paraffin is used. However, fresh- or frozen tissue is suitable.
The tests are specially matched to severely fragmented DNA (< 200 bp) extracted from FFPE tissue.
- Test for KRAS mutations particularly relating to colon cancer
- Test for BRAF mutations particularly relating to melanomas
- Test for EGFR mutations (Research Use Only) particularly relating to solid lung tumours
The test portfolio is being extended in accordance with the development of companion diagnostics.
in the Routine Clinical Laboratory - English
for KRAS mutation detection - English