{"id":3121,"date":"2024-07-01T11:58:25","date_gmt":"2024-07-01T03:58:25","guid":{"rendered":"https:\/\/opentrons.com.cn\/?post_type=knowledge2&p=3121"},"modified":"2024-09-02T18:28:23","modified_gmt":"2024-09-02T10:28:23","slug":"lzyyrnatqfapg","status":"publish","type":"post","link":"https:\/\/opentrons.com.cn\/en\/news\/lzyyrnatqfapg\/","title":{"rendered":"Evaluation of two automated low-cost RNA extraction protocols for SARS-CoV-2 detection"},"content":{"rendered":"\n
background<\/h3>\n\n\n\n
Two automated in-house protocols for high-throughput RNA extraction from nasopharyngeal swabs for the detection of SARS-CoV-2 have been evaluated.<\/p>\n\n\n\n
method<\/h3>\n\n\n\n
141 SARS-CoV-2 positive samples were collected over 10 days. The in-house protocol is based on magnetic bead extraction and is designed for use with the Opentrons OT-2 (OT-2Internal<\/sub>) liquid handling robot or the MagMAX Express-96 system (MMInternal ). Both protocols were tested in parallel with a commercial kit using the MagMAX TM system (MM Kit). Nucleic acid extraction efficiency was calculated based on the SARS-CoV-2 DNA positive control.<\/sub><\/p>\n\n\n\n
result<\/h3>\n\n\n\n
No significant differences were found between in-house protocols and commercial kits in detecting positive samples. The MM reagent kit<\/sub> was the most efficient, although the internal MM kit<\/sub> had lower average Ct values \u200b\u200bthan the other two kits. Compared to commercial kits, the in-house protocol saves \u20ac350 to \u20ac400 per 96 samples extracted.<\/p>\n\n\n\n
in conclusion<\/h3>\n\n\n\n
The described protocol utilizes readily available reagents and open source liquid handling systems and is suitable for SARS-CoV-2 detection in high-throughput facilities.<\/p>\n\n\n\n
Citation:<\/strong> L\u00e1zaro-Perona F, Rodriguez-Antol\u00edn C, Alguacil-Guill\u00e9n M, Guti\u00e9rrez-Arroyo A, Mingorance J, Garc\u00eda-Rodriguez J, et al. (2021) Evaluation of two automated low-cost RNA extraction protocols for SARS-CoV-2 detection. PLoS ONE 16(2):e0246302. https:\/\/doi.org\/10.1371\/journal.pone.0246302<\/p>\n\n\n\n
Editor:<\/strong> AM Abd El-Aty, Cairo University, Egypt<\/p>\n\n\n\n
Received:<\/strong> November 5, 2020; Accepted:<\/strong> January 15, 2021; Published:<\/strong> February 16, 2021 day<\/p>\n\n\n\n
Copyright:<\/strong> \u00a9 2021 L\u00e1zaro-Perona et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.<\/p>\n\n\n\n
Data availability:<\/strong> All relevant data are within the paper and its supporting information files.<\/p>\n\n\n\n
Funding:<\/strong> The authors received no specific financial support for this work.<\/p>\n\n\n\n
Competing Interests:<\/strong> The authors declare that there are no competing interests.<\/p>\n\n\n\n
introduce<\/h2>\n\n\n\n
The SARS-CoV-2 outbreak requires the large-scale use of qPCR testing to detect positive cases and trace contacts to stop community transmission. Before qPCR detection, RNA extraction from clinical samples is usually required [ 1-4 ]. Considering the number of samples tested daily, manual RNA extraction methods are not feasible for most institutions, therefore, automated systems are widely used for this task [5-7]. The disadvantage of an automated system is that it significantly increases the final cost, which may hinder large-scale testing in some areas. Additionally, inventory shortages of extraction reagents caused significant delays in diagnosis due to increased demand.<\/p>\n\n\n\n
This article describes two low-cost automated RNA extraction methods. The first method uses the OT-2 system (Opentrons, New York, NY, USA), an open source liquid handling robot capable of automating self-designed protocols; the second method uses MagMAX, a fast and easy-to-use nucleic acid extractor. TM<\/sup> Express-96 system (Thermo Fisher Scientific, Waltham, MA, USA). The latter can extract up to 96 samples in 30 minutes, but requires prior manual distribution of reagents, magnetic beads, and samples in the 96-well plate, which adds 30 minutes. As an alternative, the OT-2internal<\/sub> protocol can process up to 48 samples in 104 minutes, fully automated.<\/p>\n\n\n\n
method<\/h2>\n\n\n\n
Sample collection<\/h3>\n\n\n\n
Over ten days, 141 consecutive SARS-CoV-2-positive nasopharyngeal swabs with viral transport medium (Deltalab, Barcelona, \u200b\u200bSpain) were collected and stored at 4\u00b0C. Before processing, 500 \u03bcL of virus culture medium and 500 \u03bcL of 4M guanidine isothiocyanate (GTC) (Qiagen, Hilden, Germany) were mixed with 5 \u03bcg\/mL carrier RNA to inactivate the samples, and then the samples were incubated at 80\u00b0C. Heat for 2 minutes and vortex briefly to mix.<\/p>\n\n\n\n
Equipment and reagents<\/h3>\n\n\n\n
Two systems were used for automatic extraction of nucleic acids: MagMAX TM<\/sup> Express-96 deep well magnetic particle processor (King Fisher Instrument, Thermo Fisher Scientific, Waltham, MA, USA) and open system OT-2 ( Opentrons, New York, NY, USA) with GEN1 magnetic module (Opentrons, New York, NY, USA) and internal protocol. Both systems used MagMAX\u2122 Express 96 plates and deep well plates (Thermo Fisher Scientific, Waltham, MA, USA).<\/p>\n\n\n\n
Three methods were used for nucleic acid extraction: 1) MagMAX and the commercial MagMAX CORE Nucleic Acid Purification Kit (MM Kit) (Thermo Fisher Scientific, Warburg, MA, USA) were used according to the manufacturer's instructions. Elsheim); 2) The OT-2 system uses universal reagents (inside OT-2), such as ethanol (Emsure\u00ae, Merck KGaA, Darmstadt, Germany), 2-propanol (Emsure\u00ae, Merck KGaA, Darmstadt, Germany), elution buffer (Omega BIO-TEK, Norcross, GA, USA), nuclease-free water (Ambion TM<\/sup>, Thermo Fisher Scientific, MA, USA) Waltham) and magnetic beads (Mag-Bind\u00ae TotalPure NGS, Omega Bio-Tek, Norcross, GA, USA); 3) MagMAX uses the same protocol as the commercial kit, but uses reagents from the OT-2 method (MM in-house >). The in-house protocol was a modified version of the procedure described by Hui He et al. [8]. Briefly, inactivated respiratory samples were mixed with isopropyl alcohol in a 1:1 ratio to a final volume of 500 \u03bcl (Internal OT-2) and 1000 \u03bcL (Internal<\/sub>MM), Add 40 \u03bcL of magnetic beads and incubate at room temperature for 5 minutes. Next, use a magnet to pull the beads to the side of the tube and discard the supernatant. The beads were then washed twice with 500 \u03bcL of freshly prepared 70% ethanol. After the second wash, discard the 70% ethanol and air-dry the beads at room temperature. Finally, the beads were resuspended in 100 \u03bcL elution buffer and separated again with a magnet to recover the eluted viral RNA (Table 1).<\/p>\n\n\n\n