Capillary earlobe blood may be used for RNA isolation, gene expression assays and microRNA quantification

Abstract

Abstract. An increasing number of studies examining gene expression associated with diseases in children is likely, in the near future, to provide simple and easy to use methods for the isolation of RNA for gene expression profiling. Prerequisites for such studies are likely to encompass the use of small amounts of blood, as well as less invasive blood collection methods. In the current study, RNA was isolated from 20 µl capillary blood samples from the earlobes of 10 adults for quantitative PCR experiments. The results were compared with RNA isolated from venipuncture samples of the 10 samples. The expression of 4 mRNAs and 1 microRNA (miRNA), miRNA-126, was measured. The quantitative PCR results obtained with the capillary blood probes were similar to results using venous blood samples. The few differences observed may result from a variation in the blood cell composition. The use of capillary blood samples from the earlobe for gene expression analysis is likely to allow this method to be used in newborns, babies and children. In addition, such a method, using microliters of blood samples, may also be useful for other medical studies e.g., in cases where repetitive blood sampling is necessary or in patients with bleeding disorders.

Changes of standard physiological-perceptual markers and circulating MicroRNAs in response to tennis match-play: A case report of two elite players

“…Overall, our findings show that the changes of the circulating miR-133a, -486 and -126 expression rates of both players differed in response to match-play with respect to the experienced physiological-perceptual stress and the underlying fitness level. These assumptions are supported by the findings of few previous studies (Aoi et al, 2013; Mooren et al, 2014; Uhlemann et al, 2014) and facilitate, in combination with our applied minimally-invasive methodology (Wehmeier and Hilberg, 2014), the application of the examined miRs as promising biomarkers of tennis exercise physiology.…”

“…For these analyses, we applied a recent validated and minimally-invasive methodology, requiring only 20 μl capillary blood samples (Wehmeier and Hilberg, 2014). The mean C T values of the players’ miR-133a (33.7 and 32.5) and miR-486 (18.2 and 17.9) differed from those reported in a previous study (35.4 for miR-133a and 25.1 for miR-486) (Aoi et al, 2013).…”

“…No data to compare were available for the C T values of the miR-126. The observed differences in the C T values may be related to the different blood samples used (Wehmeier and Hilberg, 2014). While we analyzed capillary whole blood, venous blood serum had been examined in a previous study (Aoi et al, 2013).…”

“…While we analyzed capillary whole blood, venous blood serum had been examined in a previous study (Aoi et al, 2013). In contrast to blood serum, capillary blood still contains cells, which may contribute to the differences in observed C T values (Wehmeier and Hilberg, 2014). Since all C T values of this study were below the cut-off value of 35 PCR cycles, where circulating miRs are difficult to quantify (Aoi et al, 2013), our results are appropriate and allow further discussions.…”

“…The changes of the circulating miR-133a, 486 and -126 expression rates were analyzed according to the methodology developed by Wehmeier and Hilberg (2014). Similarly to lactate analyses, the changes of the circulating miRs were determined from 20 μl capillary blood samples, which were collected with EDTA-coated capillaries (Sarstedt) and added into tubes filled with 1 ml PeqGold reagents (PeqLab, Erlangen, Germany).…”