Method For Total RNA Extraction Research Articles

Comparison of Fecal MicroRNA Isolation Using Various Total RNA Isolation Kits.

Fecal specimens have long been regarded as promising sources for gastrointestinal cancer screening and have, thus, been extensively investigated in biomarker research. MicroRNAs (miRNAs) are small, non-coding RNA molecules involved in regulating various biological processes. They are commonly dysregulated during tumor development and exhibit differential expression in feces. To assess the preanalytical feasibility of fecal miRNA analysis, we systematically compared the performance of commonly used total RNA extraction methods. Fecal samples from healthy subjects were utilized for this evaluation. Various methods, including miRNeasy, Universal, Trizol, RNeasy, and mirVana kits, were employed to isolate total RNA. MiRNA expression analyses were conducted using TaqMan or SYBR Green qRT-PCR for a subset of miRNAs, with externally spiked-in cel-miR-39 used for normalization. Most methods demonstrated similar performance in terms of the total RNA concentration and purity. Externally spiked cel-miR-39 and endogenous miRNAs (RNU6b, miR-16, and miR-21) exhibited comparable concentrations across the different RNA isolation methods, whereas the RNeasy mini kit consistently yielded lower values. Our findings suggest that various isolation methods produce reproducible and comparable miRNA expression results, supporting the potential comparability and translational applicability of miRNA-based biomarker research in the future.

Optimizing total RNA extraction method for human and mice samples.

Extracting high-quality total RNA is pivotal for advanced RNA molecular studies, such as Next-generation sequencing and expression microarrays where RNA is hybridized. Despite the development of numerous extraction methods in recent decades, like the cetyl-trimethyl ammonium bromide (CTAB) and the traditional TRIzol reagent methods, their complexity and high costs often impede their application in small-scale laboratories. Therefore, a practical and economical method for RNA extraction that maintains high standards of efficiency and quality needs to be provided to optimize RNA extraction from human and mice tissues. This study proposes enhancements to the TRIzol method by incorporating guanidine isothiocyanate (GITC-T method) and sodium dodecyl sulfate (SDS-T method). We evaluated the effectiveness of these modified methods compared to the TRIzol method using a micro-volume UV-visible spectrophotometer, electrophoresis, q-PCR, RNA-Seq, and whole transcriptome sequencing. The micro-volume UV-visible spectrophotometer, electrophoresis, and RNA-Seq demonstrated that the GITC-T method yielded RNA with higher yields, integrity, and purity, while the consistency in RNA quality between the two methods was confirmed. Taking mouse cerebral cortex tissue as a sample, the yield of total RNA extracted by the GITC-T method was 1,959.06±49.68 ng/mg, while the yield of total RNA extracted by the TRIzol method was 1,673.08±86.39 ng/mg. At the same time, the OD260/280 of the total RNA samples extracted by the GITC-T method was 2.03±0.012, and the OD260/230 was 2.17±0.031, while the OD260/280 of the total RNA samples extracted by the TRIzol method was 2.013±0.041 and the OD260/230 was 2.11±0.062. Furthermore, q-PCR indicated that the GITC-T method achieved higher yields, purity, and greater transcript abundance of total RNA from the same types of animal samples than the TRIzol method. The GITC-T method not only yields higher purity and quantity of RNA but also reduces reagent consumption and overall costs, thereby presenting a more feasible option for small-scale laboratory settings.

Circulating exosomal microRNAs as biomarkers of lupus nephritis.

Disruption in the delicate symphony of genes, microRNA (miRNA), or protein expression can result in the dysregulation of the immune system, leading to the devastating consequences such as lupus nephritis (LN). The capacity of exosomes to transport miRNAs between cells and modify the phenotype of recipient cells implies their involvement in persistent kidney inflammation. This study unveils identifying two previously undiscovered exosomal miRNAs in the serum of LN patients, offering potential solutions to the current challenges in LN diagnosis and management. Initially, we used a reagent-based kit to isolate serum exosomes from patients with Systemic lupus erythematosus (SLE) and used Trizol method for total RNA extraction. Subsequently, we employed small RNA sequencing to screen for differential expression profiles of exosomal small RNAs. The RT-qPCR method was used to individually validate samples in both the screening and validation cohorts, enabling the identification of candidate small RNAs; specific to LN. We assessed the diagnostic potency using receiver operating characteristic (ROC) curve, and explored the biological roles of miRNAs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Compared to SLE patients without LN, SLE patients accompanied by LN exhibited significantly spiked levels of exosomal hsa-miR-4796-5p and hsa-miR-7974. The duo of miRNAs, hsa-miR-4796-5p and hsa-miR-7974, exhibited promising potential as biomarkers for diagnosing LN, with an AUC exceeding 0.8. Correlation analysis revealed a strong positive association between these miRNAs and proteinuria, as well as the SLE Disease Activity Index (SLEDAI) score. Moreover, the levels of two miRNAs in LN patients were significantly elevated in comparison to other autoimmune nephritis conditions, such as immunoglobulin A nephropathy (IgAN) and diabetic nephropathy (DN). Furthermore, the bioinformatics analysis indicated that this miRNAs duo can play a pivotal role in the regulation of immune processes by modulating signal pathways, such as the mTOR and PI3K-Akt signaling pathway. This study provides a new ground that serum exosomal miRNAs can effectively identify and predict LN in SLE patients.

Small RNA Profiling by Next-Generation Sequencing Using High-Definition Adapters.

Next-generation sequencing (NGS) of small RNA (sRNA) cDNA libraries permits the identification and characterization of sRNA species de novo. However, the method through which these libraries are constructed can often introduce artifacts such as over- or underrepresentation of specific sequences or adapter oligonucleotides due to sequence biases held by the enzymes used. In this chapter we describe a protocol for sRNA library construction making use of high-definition (HD) adapters for the Illumina sequencing platform, which reduce ligation bias. This protocol leads to drastically reduced direct 5'/3' adapter ligation products and can be used for the synthesis of sRNA libraries from total RNA or sRNA of various plant, animal, and fungal samples. This protocol also includes a method for total RNA extraction from plant leaf and cultured cells or body fluids.

Comparison and Improvement of Total RNA Extraction Methods from Different Tissues of <i>Polygonatum cyrtonema</i> Hua

Comparison and Improvement of Total RNA Extraction Methods from Different Tissues of <i>Polygonatum cyrtonema</i> Hua

A rapid One-Pot RNA isolation method for simplified clinical detection of SARS-COV-2 infection in India

BackgroundWith the rapid increase in COVID-19 cases and the discovery of new viral variants within India over multiple waves, the expensive reagents and time-consuming sample pretreatment required for qPCR analysis have led to slower detection of the disease. The vast Indian population demands an inexpensive and competent sample preparation strategy for rapid detection of the disease facilitating early and efficient containment of the disease.MethodsIn this study, we have surveyed the spread of COVID-19 infection over Faridabad, Haryana, India for 6 months. We also devised a simple single-step method for total RNA extraction using a single tube and compared its efficacy with the commercially available RNA isolation kits.FindingsOur findings suggest that determining Ct values for samples subjected to the One Pot RNA extraction method was as efficient as the commercially available kits but delivers a subtle advantage in a way, by minimizing the cost, labor and sample preparation time.ConclusionThis novel crude RNA extraction method is stable and capable of operating in developing countries like India for low resource settings, without the use of expensive reagents and instruments. Additionally, this method can be further adapted to pooling samples strategies owing to its high sensitivity.

Optimization of nucleic acid extraction and amplification of a thiamine biosynthesis gene fragment from selected Malaysian seaweeds.

Obtaining high-quality nucleic acid extracted from seaweeds is notoriously difficult due to contamination with polysaccharides and polyphenolic compounds after cell disruption. Specific methods need to be employed for RNA isolation in different seaweed species, and therefore studies of the thiamine biosynthesis pathway have been limited. Two selected Malaysian species which are highly abundant and underutilized, namely Gracilaria sp. and Padina sp., representing the red and brown seaweeds, respectively, were collected to develop optimized total RNA extraction methods. Prior to that, DNA was extracted, and amplification of the 18S rRNA gene and the THIC gene (encoding the first enzyme in the pyrimidine branch of the thiamine biosynthesis pathway) from the DNA template was successful in Gracilaria sp. only. RNA was then extracted from both seaweeds using three different existing methods, with some modifications, using cetyltrimethylammonium bromide, guanidine thiocyanate and sodium dodecyl sulphate. Methods I and III proved to be efficient for Padina sp. and Gracilaria sp., respectively, for the extraction of highly purified RNA, with A260/A280 values of 2.0 and 1.8. However, amplification of the housekeeping gene glyceraldehyde-3-phosphate dehydrogenase and the THIC gene was successful in only Gracilaria sp. cDNA derived from extracted RNA. Further modifications are required to improve the exploitation of nucleic acids from brown seaweeds, which has been proven to be difficult. This work should pave the way for molecular studies of seaweeds generally and for the elucidation, specifically, of the thiamine biosynthesis pathway.

A comparison of total RNA extraction methods for RT-PCR based differential expression of genes from Trichoderma atrobrunneum

The genus Trichoderma is ubiquitous in various niches and is currently used for biocontrol, biofertilizer, enzyme production and bioremediation. However, molecular mechanisms underlying its diverse biological functions are yet not fully elucidated. Extraction of high-quality RNA for downstream applications such as quantitative polymerase chain reaction is a prerequisite. The current study aims to optimize a total RNA extraction protocol for high-quality and quantity RNA from Trichoderma atrobrunneum. Seven RNA extraction protocols including Trizol, RiboEx PureLink RNA mini kit, high salt CTAB (cetyltrimethylammonium bromide), modified high salt CTAB, SDS (sodium dodecyl sulfate) and CTAB-PVP (polyvinylpyrrolidone) were performed separately, to extract RNA. Quality and quantity of extracted RNA samples were further analyzed by Nanodrop spectrophotometry, agarose gel electrophoresis and RT-PCR analysis. The results of quantitative and qualitative analysis of RNA samples showed that more intact, high-quality RNA was extracted using the modified high salt CTAB as compared to other methods. The RT-PCR results for the amplification of the genes encoding β-tubulin and Ubiquitin carrier protein also showed lowest threshold cycle (Ct) and coefficient of variation (CV) for RNA samples extracted with the modified high salt CTAB method as compared to RNA samples extracted with other protocols. Therefore, it is proposed that the modified high salt CTAB protocol is an excellent method to obtain high-quality RNA with good yield from T. atrobrunneum for its downstream applications. Moreover, the optimized protocol is very economical and can be used to extract total RNA from a large number of samples.

An investigation into simplifying total RNA extraction with minimal equipment using a low volume, electrokinetically driven microfluidic protocol.

Current methods for total RNA extraction are time-consuming and require several hands-on steps and specialized equipment. Microfluidic devices can offer the opportunity to reduce the number of hands-on steps, decrease the volumes of reagents required for purification, and make extraction high throughput. Here, we investigated the translation of a high volume magnetic bead-based total RNA extraction method (from human whole blood) onto a low input volume microfluidic device. Our results first show that RNA integrity is maintained when the reagent volumes are scaled down by a factor of 22 and the wash buffers are combined 1:1. With our microfluidic method, the number of wash steps can be reduced from four to one. Thus, the time to complete RNA extraction can be reduced from 2 h to 40 min. These manipulations to the conventional protocol yielded RNA amplifiable within 40 cycles of reverse transcription quantitative PCR (RT-qPCR) when using the microfluidic device to simplify the wash steps. To improve the purification of the RNA during the bead transport through the microchannel, we also investigated the effect of a synergetic application of the electrokinetic flow. Our results show that DNase I and other contaminants surrounding the beads get washed away more effectively via electrophoretic transport. Most notably, RNA adsorption on the beads is strong enough to counter electrophoretically-driven desorption. In all, our work opens new ways to extract high-quality total RNA rapidly and simply from a small quantity of blood, making the process of RNA extraction more accessible.

An optimized method for RNA extraction from the polyurethane oligomer degrading strain Pseudomonas capeferrum TDA1 growing on aromatic substrates such as phenol and 2,4-diaminotoluene.

Bacterial degradation of xenobiotic compounds is an intense field of research already for decades. Lately, this research is complemented by downstream applications including Next Generation Sequencing (NGS), RT-PCR, qPCR, and RNA-seq. For most of these molecular applications, high-quality RNA is a fundamental necessity. However, during the degradation of aromatic substrates, phenolic or polyphenolic compounds such as polycatechols are formed and interact irreversibly with nucleic acids, making RNA extraction from these sources a major challenge. Therefore, we established a method for total RNA extraction from the aromatic degrading Pseudomonas capeferrum TDA1 based on RNAzol® RT, glycogen and a final cleaning step. It yields a high-quality RNA from cells grown on TDA1 and on phenol compared to standard assays conducted in the study. To our knowledge, this is the first report tackling the problem of polyphenolic compound interference with total RNA isolation in bacteria. It might be considered as a guideline to improve total RNA extraction from other bacterial species.

Evaluation of U.S. Food and Drug Administration Enteric Viruses Microarray for Detection of Hepatitis A Virus and Norovirus in Inoculated Tomatoes, Green Onions, and Celery

Foodborne viral contamination of fresh produce has been associated with numerous outbreaks. Detection of such contaminated foods is important in protecting public health. Here, we demonstrate for the first time the capability of the U.S. Food and Drug Administration Enteric Viruses tiling microarray (FDA-EVIR) to perform rapid molecular identification of hepatitis A virus (HAV) and human norovirus extracted from artificially inoculated fresh produce. Two published viral extraction strategies, total RNA extraction or virus particle isolation, were used to prepare the viral targets. The total RNA extraction method was used on material eluted from tomatoes, using an alkaline Tris-glycine-beef extract (TGBE) buffer. Optimization procedures including DNase treatment and poly(A)-RNA enrichment were adopted to improve microarray sensitivity. For green onions or celery, material was eluted using either glycine buffer or TGBE buffer supplemented with pectinase, respectively, and then virus particles were concentrated by ultracentrifugation. We also assessed the amount of viral RNA extracted from celery using three commercially available kits and how well that RNA performed on FDA-EVIR. Our results confirm that FDA-EVIR can identify common enteric viruses isolated from fresh produce when present as either a single or mixed species of viruses. Using total RNA extraction from tomatoes yielded a limit of detection of 1.0 × 105 genome equivalents (ge) of HAV per array input. The limit of detection for viral RNA obtained using ultracentrifugation was 1.2 × 105 ge of HAV from green onions and 1.0 × 103 ge of norovirus from celery per array input. Extending microarray methods to other food matrices should provide important support to surveillance and outbreak investigations.

The guanidine thiocyanate-high EDTA method for total microbial RNA extraction from severely heavy metal-contaminated soils.

SummaryMolecular analyses relying on RNA, as a direct way to unravel active microbes and their functional genes, have received increasing attention from environmental researchers recently. However, extracting sufficient and high‐quality total microbial RNA from seriously heavy metal‐contaminated soils is still a challenge. In this study, the guanidine thiocyanate‐high EDTA (GTHE) method was established and optimized for recovering high quantity and quality of RNA from long‐term heavy metal‐contaminated soils. Due to the low microbial biomass in the soils, we combined multiple strong denaturants and intense mechanical lysis to break cells for increasing RNA yields. To minimize RNAase and heavy metals interference on RNA integrity, the concentrations of guanidine thiocyanate and EDTA were increased from 0.5 to 0.625 ml g−1 soil and 10 to 100 mM, respectively. This optimized GTHE method was applied to seven severely contaminated soils, and the RNA recovery efficiencies were 2.80 ~ 59.41 μg g−1 soil. The total microbial RNA of non‐Cr(VI) (NT) and Cr(VI)‐treated (CT) samples was utilized for molecular analyses. The result of qRT‐PCR demonstrated that the expressions of two tested genes, chrA and yieF, were respectively upregulated 4.12‐ and 62.43‐fold after Cr(VI) treatment. The total microbial RNA extracted from NT and CT samples, respectively, reached to 26.70 μg and 30.75 μg, which were much higher than the required amount (5 μg) for metatranscriptomic library construction. Besides, ratios of mRNA read were more than 86%, which indicated the high‐quality libraries constructed for metatranscriptomic analysis. In summary, the GTHE method is useful to study microbes of contaminated habitats.

An efficient method for total RNA extraction from leaves of arboreal species from the Brazilian Cerrado

Abstract Considering the lack of information on RNA extraction from arboreal species, specially from the Brazilian Cerrado, the aim of this study was to test RNA extraction methods for a wide variety of native plant species from this biome. The methods tested consisted of: (i) TRIzol® reagent, (ii) TRIzol® reagent with modifications, (iii) CTAB buffer, and (iv) Modified CTAB buffer, initially for leaf samples of Xylopia aromatica and Piper arboreum. Later the procedure with the best results was used to obtain purified RNA from 17 other native species. Based on A260/A280 absorbance ratio the Modified CTAB method was the best for total RNA extraction for those woody species. Ten out of eleven species tested through RT-PCR generated fragments of the expected size from the total RNA extracted by the selected method, confirming it as the best option to obtain high-quality RNA for molecular analyses and for use in the detection of viruses infecting these tree species.

The effects of pH and salts on nucleic acid partitioning during phenol extraction

The partitioning of nucleic acids is sensitive to pH during phenol extraction. However, the exact effects of pH on phenol extraction had not been systematically investigated, and the mechanism of which were not fully elucidated. In this paper, we showed that the partitioning of nucleic acids was determined neither solely by the pH of the aqueous buffer being used, nor by the “pH of the phenol”; the latter is a completely wrong conception. We demonstrated that a key determinant for nucleic acid partitioning during phenol extraction was the equilibrated pH of the aqueous phase, which should be defined as the pH of phenol extraction. For example, when 50 mM NaAc-HAc buffer at pH of 3.47 was mixed with an equal volume of water-saturated phenol, the equilibrated pH of aqueous phase would be raised to ∼3.84. At this pH, almost all of genomic DNA partitioned into the phenol phase, and genomic DNA-free total RNA was retained in the aqueous phase. Several salts were found affecting the partitioning of nucleic acids during phenol extraction in different manners. Based on these results, a low-cost and efficient method for genomic DNA-free total RNA extraction was developed.

Studies on Total RNA Extraction Methods from the Stems of Dendrobium Species

Studies on Total RNA Extraction Methods from the Stems of Dendrobium Species

Total RNA extraction from tissues for microRNA and target gene expression analysis: not all kits are created equal

BackgroundmicroRNAs (miRNAs) are short non-coding RNAs that fine-tune gene expression. The aberrant expression of miRNAs is associated with many diseases and they have both therapeutic and biomarker potential. However, our understanding of their usefulness is dependent on the tools we have to study them. Previous studies have identified the need to optimise and standardise RNA extraction methods in order to avoid biased results. Herein, we extracted RNA from murine lung, liver and brain tissues using five commercially available total RNA extraction methods. These included either: phenol: chloroform extraction followed by alcohol precipitation (TRIzol), phenol:chloroform followed by solid-phase extraction (column-based; miRVana and miRNeasy) and solid-phase separation with/without affinity resin (Norgen total and Isolate II). We then evaluated each extraction method for the quality and quantity of RNA recovered, and the expression of miRNAs and target genes.ResultsWe identified differences between each of the RNA extraction methods in the quantity and quality of RNA samples, and in the analysis of miRNA and target gene expression. For the purposes of consistency in quantity, quality and high recovery of miRNAs from tissues, we identified that Phenol:chloroform phase separation combined with silica column-based solid extraction method was preferable (miRVana microRNA isolation). We also identified a method that is not appropriate for miRNA analysis from tissue samples (Bioline Isolate II). For target gene expression any of the kits could be used to analyse mRNA, but if interested in analysing mRNA and miRNA from the same RNA samples some methods should be avoided.ConclusionsDifferent methods used to isolate miRNAs will yield different results and therefore a robust RNA isolation method is required for reproducibility. Researchers should optimise these methods for their specific application and keep in mind that “total RNA” extraction methods do not isolate all types of RNA equally.

An Improved Total RNA Extraction Method for White Jelly Mushroom Tremella fuciformis Rich in Polysaccharides

An improved method for extracting high quality and quantity RNA from a jelly mushroom and a dimorphic fungus—Tremella fuciformis which is especially rich in polysaccharides, is described. RNA was extracted from T. fuciformis mycelium M1332 and its parental monokaryotic yeast-like cells Y13 and Y32. The A260/280 and A260/230 ratios were both approximately 2, and the RNA integrity number was larger than 8.9. The yields of RNA were between 108 and 213 μg/g fresh wt. Downstream molecular applications including reverse transcriptional PCR and quantitative real-time PCR were also performed. This protocol is reliable and may be widely applicable for total RNA extraction from other jelly mushrooms or filamentous fungi rich in polysaccharides.

High-quality total RNA isolation from melon (Cucumis melo L.) fruits rich in polysaccharides

Melon, a member of the family Cucurbitaceae, is the fourth most important fruit in the world market and, on a volume basis, is Brazil’s main fresh fruit export. Many molecular techniques used to understand the maturation of these fruits require high concentrations of highly purified RNA. However, melons are rich in polyphenolic compounds and polysaccharides, which interfere with RNA extraction. This study aimed to determine the most appropriate method for total RNA extraction from melon fruits. Six extraction buffers were tested: T1) guanidine thiocyanate/phenol/chloroform; T2) sodium azide/?-mercaptoethanol; T3) phenol/guanidine thiocyanate; T4) CTAB/PVP/?-mercaptoethanol; T5) SDS/sodium perchlorate/PVP/?-mercaptoethanol, and T6) sarkosyl/PVP/guanidine thiocyanate, using the AxyPrepTM Multisource Total RNA Miniprep Kit. The best method for extracting RNA from both mature and green fruit was based on the SDS/PVP/?-mercaptoethanol buffer, because it rapidly generated a high quality and quantity of material. In general, higher amounts of RNA were obtained from green than mature fruits, probably due to the lower concentration of polysaccharides and water. The purified material can be used as a template in molecular techniques, such as microarrays, RT-PCR, and in the construction of cDNA and RNA-seq data.

Development of one-tube real-time qRT-PCR and evaluation of RNA extraction methods for the detection of Eggplant mottled dwarf virus in different species

A one-tube real-time qRT-PCR assay was developed, for the detection and quantification of Eggplant mottled dwarf virus (EMDV), a pathogen affecting cultivated and ornamental plants. The amplification efficiency of the assay was 98% and the linear range of quantification was from 20 to 2×108 RNA transcripts. Total RNA extraction methods (three developed methods and one commercially available RNA extraction kit) were evaluated using tissues from seven different plant species and synthetic EMDV RNA transcripts of known concentration. The recovery rates of RNA and the effect of co-extracted inhibitors revealed that methods involving PVPP and phenol–chloroform extraction were the most efficient. These modifications were necessary for processing samples containing high phenolic and polysaccharide compounds such as woody plants. The developed EMDV detection protocol was successfully applied in forty naturally infected woody and herbaceous plants belonging to six different species. The protocol comprises a useful method for low-cost detection of ssRNA viruses in diverse plant tissues.

One improved method for the extraction of total RNA from rat bone

Objective To introduce one method to improve the effect of bone RNA extraction when the classical Trizol method can not meet the experimental requirements.Methods The concentration,purity and integrity of the extracted RNA were tested.The RNA was reversely transcripted into cDNA,as a template which was then amplified to DNA.Results The re-extracted RNA could be fully dissolved by diethyl chlorophosphate (DEPC) water.This method could effectively reduce the interference of mucin carbohydrate.After the prevention of the sodium mixture solution,the concentration of the RNA was slightly lower than that before the prevention.The rate of A260/A280 and A260/A230 of RNA was both significantly higher afher the prevention than that before the prevention [(1.96 ± 0.11) vs.(1.52 ± 0.05),(1.90 ±0.21) vs.(0.27 ±0.08) respectively].Agarose gel electrophoresis showed the RNA after prevention was complete and the polymerase chain reaction (PCR) procession could successfully amplify the targeted gene.Conclusion The improved extraction method could insure the purity,concentration and integrity of RNA,and meet the requirements for molecular research. Key words: Bone tissue; RNA extraction; Rats