The WHO 1st International Reference Panel for genomic KRAS codons 12 and 13 mutations (NIBSC product code 16/250) comprises eight freeze-dried human genomic DNA materials produced from cell lines covering the seven most-common CRC-associated KRAS mutations, as found in codons 12 and 13, plus a wild-type KRAS standard (and diluent).
These primary standards support cancer genomic diagnostics as they can be used to calibrate diagnostic assays, kits, and secondary standards for the seven most-common KRAS mutations.
The panel was validated in an international collaborative study involving 56 laboratories and shows suitability as standards in next-generation sequencing (NGS), Sanger sequencing, real-time PCR, pyrosequencing, digital PCR (dPCR), Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometric analysis (MassARRAY®), KRAS StripAssay®, high resolution melt analysis (HRM), Amplification Refractory Mutation System-PCR (ARMS-PCR), PCR-Reverse Sequence Specific Oligonucleotide probe technique (PCR-rSSO), minisequencing, and restriction fragment length polymorphism analysis (RFLP).
KRAS mutations can be found in around 30% cancers including lung, pancreas and colon. For colorectal cancer, over 90% of KRAS mutations occur in codons 12 and 13. Genetic testing is now often required before decisions on cancer treatment can be made and accurate diagnostic methods are critical to ensure a patient receives the right therapy at the right time.
The genotype and consensus KRAS mutation percentage for each of the eight materials in the WHO 1st International Reference Panel for genomic KRAS codons 12 and 13 mutations is shown below, along with the consensus mutant KRAS and total KRAS copy number.
End-users are able to further dilute the mutant materials (with wild-type KRAS codons 12 and 13 material 16/266, or another wild-type genomic DNA calibrated to material 16/266) using a dilution formula based on the mutant and total KRAS copy numbers to achieve further standards at a range of lower consensus mutation percentages from which assay calibration may be achieved.
The dilution response curve for each material was derived from the collaborative study data, with the model verified at lower dilutions by in-house ddPCR.
Dilutions of the mutant KRAS codons 12 and 13 materials may be established by use of a formula, pre-calculated dilutions or by reference to interactive dilution curves.
Details of the formula and pre-calculated dilutions can be found in the product IFU.Interactive dilution curves can be viewed in Google Chrome using this link. The link is not guaranteed to work in other browsers.
Dr Ross Hawkins – Section HeadDr Ravneet BhullerMr Malcolm Hawkins Dr Leandro Lo CascioMr Noble OssaiDr Pia SanzoneMr Miltiades Stylianou
16/250: KRAS codons 12 and 13 (WHO)Other genomic reference materials
Further information on ordering genomic reference materials from NIBSC.