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Updated: Jan 5, 2026

Digital PCR for Quantifying Circulating MicroRNAs in Acute Myocardial Infarction and Cardiovascular Disease
Published on: July 3, 2018
Optimizing miR-29 measurements in biobanked, heparinized samples
Catherine M Warnement1, Mary J Cismowski2, Lynette K Rogers3
1Center for Perinatal Research, Abigail Wexner Research Institute at Nationwide Children's Hospital, USA.
Aims:
MicroRNAs (miRs) and their importance in development, normal physiology, and disease have become increasingly recognized. Our laboratory is interested in miR-29 and its effects on lung development. These studies set out to identify optimal conditions for the measurement of miR-29 in heparinized, biobanked samples and to compare isoform expression patterns.
Materials And Methods:
The efficiency of three distinct heparinases were tested using reverse transcriptase polymerase chain reaction (RT-PCR): recombinant F. Heparinum heparinase I; recombinant P. heparinus heparinase II; recombinant P. heparinus heparinase III; and heparinase I (B. efferthii-derived). The effects of freeze/thaws, and the relative expression of different miR-29 isoforms were also assessed using RT-PCR.
Key Findings:
Our investigations determined that heparinase 1 (recombinant F. Heparinum) and 2 (recombinant P. heparinus) at 1 or 2 h incubation efficiently neutralized heparin activity and prevented interference with the PCR. Also, a single freeze/thaw did not affect the measurement of miR-29-3p but multiple freeze/thaw cycles decreased the measureable miR levels. Finally, the -3p strand was most abundantly expressed in all three isoforms in both human and mouse plasma.
Significance:
Our findings illustrate that specific conditions need to be optimized for the particular miR and the type of sample being tested.

