Optimized methods for extracting circulating small RNAs from long-term stored equine samples

Table 1 Small RNA extraction kit comparison

Kit	Horse ID	Serum volume (μl)	RNA concentration, Nanodrop (ng/μl)	Elution volume (μl)	Small RNA concentration, Bioanalyzer (pg/μl)	miRNA in small RNA (%)	miRNA/100 μl serum (ng)
ZR WB	1	200	1.85	8	89.4	46	0.17
ZR WB	3	200	3.65	8	69.5	63	0.18
Direct-zol	1	100	2.70	50	15.0	86	0.64
Direct-zol	3	100	0.45	50	12.8	53	0.34
miRNeasy	1	200	56.23	12	30.4	72	0.13
miRNeasy	3	200	11.69	12	126.2	77	0.58
TRIzol	1	400	52.98	10	138.5	63	0.22
TRIzol	3	400	138.21	10	127.9	43	0.14

RNA extraction results with different kits used. Due to differences in serum and elution volumes used, the RNA/miRNA concentration is given in RNA per 100μl of serum. RNA was measured with Nanodrop and miRNA with Bioanalyzer. The concentration was not measurable with the Qubit high sensitivity RNA kit. Due to very low concentration, the Nanodrop results should be treated with caution

ISSN: 1751-0147