Reproducibility of mutation detection in FFPE specimens. Two large colon cancer
resections were repeatedly tested in separate process batches. DNA was first
extracted from all of the tissue in each FFPE block in several batches, pooled,
and then used to make 200 ng aliquots. The reproducibility of mutation detection
and measured MAF were examined. The MAF measured for the known somatic
alterations in these samples is shown, with samples ordered left to right from
earliest to latest. (a) One specimen was tested 79 times between
November 9, 2011 and June 17, 2012. Three known somatic mutations (COSMIC) were
detected in this sample: APC c.4394-4395insAG
p.S1465fs*9, KRAS c.35G>A p.G12D, and
PTEN c.235G>A p.A79T. Each of these mutations was
successfully detected in 79/79 tests. (b) A second specimen was
tested 71 times between July 12, 2012 and October 21, 2012. Two known somatic
mutations were detected in this sample: APC c.694C>T
p.R232* and KRAS c.35G>T p.G12V. Each of these
mutations was successfully detected in 71/71 tests.