ABSTRACT
BACKGROUND: The ORI-EGI-02 study was designed to test the hypothesis that rectal mucus collected using a novel rectal sampling device (OriCol™), contains sufficient human deoxyribonucleic acid (DNA) of the required quality for Next Generation Sequencing (NGS), for colorectal disease genetic signature discovery. METHODS: Using National Institute for Health and Care Research methodology, an internal pilot study was performed in January 2020-May 2021, at four sites in the United Kingdom, to assess the process of recruitment, consent, specimen acquisition and viability for analysis. Following an OriCol™ test, the sample was stabilized with a buffer solution to preserve the material, which was posted to the laboratory. Samples were processed using QIAamp® DNA Blood Midi kit to extract DNA and Quant-iT™ PicoGreen® dsDNA Reagent to quantify the retrieved DNA. DNA integrity was measured by Agilent TapeStation system. 25 ng of human amplifiable DNA was prepared for Next Generation Sequencing (NGS), which was performed on an Illumina NextSeq550 sequencer using the 300-cycle high output kit v2.5. RESULTS: This study assessed the first 300 patients enrolled to the ORI-EGI-02 Study (n = 800). 290/300 (96.67%) were eligible to undergo OriCol™ sampling procedure and 285/290 (98.27%) had a successful OriCol™ sample taken. After transportation, extraction and quantification of DNA, 96.20% (279/290) of the samples had NGS successfully performed for bioinformatic analysis. CONCLUSIONS: Our internal pilot study demonstrated that the OriCol™ sampling device can capture rectal mucus from unprepared bowel in subjects who could undergo a digital rectal examination. The technique could be applied irrespective of age, frailty, or co-morbidity. Completion of the study to 800 patients and analysis of NGS data for colorectal cancer mutations will now proceed.
