Microsatellite instability testing (MSI) for colorectal mucinous adenocarcinoma . MSI testing was performed using the 5-marker panel recommended by the National Cancer Institute. The laboratory routinely used 500 ng gDNA for this test. Similar peak height was obtained with 10-fold less DNA isolated by the newly developed extraction method (Figure 5). A: normal tissue; B: using tumor DNA extracted by the traditional method (U-SQ); C: using tumor DNA extracted by the new method (H-PQ).