Data from: Endoscopic liquid biopsies of gastric fluid in a large human patient cohort reveal DNA content as a candidate tumor biomarker in gastric cancer

Patient data: collected from medical records. 
DNA extraction and quantification: DNA was extracted from gastric
fluids that are routinely removed to allow better examination of the
mucosa. These fluids were collected in sterile plastic containers attached
to the endoscope suction channel and kept on ice until pH measurement and
neutralization. Samples were divided in aliquots and kept frozen at
-20^oC (each aliquot was thawed just once), until
DNA was extracted from an equal volume of gastric fluid (800 µl) by
proteinase-K digestion, followed by phenol-chloroform extraction and
ethanol DNA precipitation. DNA was subsequently resuspended in 100 µl of
sterile nuclease-free double-deionized water and quantified by Qubit
fluorometry (Thermo Fisher).