Obtaining RNA control sample and prospects of its application for diagnostics of yellow fever by the LAMP method

The aim of the study was to create a control RNA sample for yellow fever virus (YFV) diagnostics using the LAMP method. Two control samples were obtained: recombinant plasmid DNA (pCR2.1-YFV-K+) and mRNA (RNA-YFV-K+). During the assessment of the analytical sensitivity by the LAMP method, it was found that both samples demonstrated a comparable detection limit of 104 copies/ml, which allows for effective detection of the viral genetic material in the first days of disease symptoms. A study of the sample stability showed that at a temperature of -15 to -25 °C, both samples retain their functionality even after tenfold defrosting/freezing. At a temperature of 2 to 8 °C, the samples are determined as positive for 7 days of storage. However, stability decreases at room temperature: for pCR2.1-YFV-K+ it remains up to 72 hours, and for RNA-YFV-K+ — up to 48 hours. To ensure stability, samples should be stored at low temperatures (-15 to -25°C or 2 to 8°C). Based on the results, RNA-YFV-K+ can be used as a control for analytical sensitivity and correctness of the reverse transcription reaction followed by amplification by the LAMP method, which is important for the detection of RNA-containing yellow fever virus.