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Abstract Background Various conditions with cellular decay are associated with elevated cell-free DNA (cfDNA). This study aimed to investigate if perioperatively measured cfDNA levels were associated with the surgical approach, complications, or recurrence. Methods Plasma was obtained from patients who underwent surgery for colon cancer at admission and at the time of discharge. Quantitative measurement of cfDNA was performed by amplifying two amplicons of 102 base pairs (bp) and 132 bp of Beta-2-Microglobulin (B2M) and Peptidyl-Prolyl cis–trans Isomerase A (PPIA), respectively. Results cfDNA was measured in 48 patients who underwent surgery for colonic cancer. Sixteen patients had recurrence during the follow-up period, fifteen developed a postoperative complication, and seventeen patients developed neither, acting as the control group. Postoperative cfDNA levels were significantly elevated from baseline samples, across all groups, with a median preoperatively B2M level of 48.3 alleles per mL and postoperatively of 220 alleles per mL and a median preoperatively level PPIA of 26.9 alleles per mL and postoperatively of 111.6 alleles per mL (p

Abstract Identification of target tissue microRNAs (miR) using in situ hybridization (ISH), with digoxigenin-labeled locked nucleic acid (LNA) probes, is influenced by preanalytic parameters. To determine the best retrieval method for common microRNAs, a multiblock composed of paraffin-embedded tonsil, cervix, placenta, and hyperplastic prostate tissue were included. Tissue were fixed in 10% formalin in a range of 5–144 hours (h). Cut sections (5 μm) from the multiblock were subjected to combinations of pretreatment procedures: variable periods of proteinase K (PK) digestion or Heat-induced microRNA Retrieval (HmiRR) using target retrieval solution (TRS) pH 6.1 or 9, with or without enzymatic treatment (pepsin). Results for the overall categories: TRS pH 9 versus PK; p = 2.9e−23, TRS pH 9 versus TRS pH 6.1; p = 1.1e−14, TRS pH 6.1 versus PK; p = 2.9e−03. A long fixation time, resulted in the best microRNA preservation and staining intensity (long vs. short: p = 3.5e−47, long vs. moderate: p = 1.6e−44, moderate vs. short: p = 4.3e−16), was enhanced using HmiRR TRS pH 9 with or without pepsin providing high sensitivity and specificity. These observations conflict with other ISH techniques (e.g., messenger ribonucleic acid), which typically require shorter fixation periods, and therefore, further studies are warranted.