Polymerase chain reactions (PCR) are most reliable and precise means for nucleic acid analysis of biological samples. A cold-chain system with temperature at around -20°C is generally necessary for storage and transportation of PCR-related reagents. In order to facilitate ambient temperature storage and transportation, this study prepared Taq DNA polymerase and 5 × HS-Taq Mix (as low as 0.5 U/sample) into stable solid formulations using an optimized freeze-drying process and lyoprotectant formulations comprising trehalose dihydrate (3.3∼5%, w/v) and mannitol (10%, w/v). The lyocakes were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). In the optimized freeze-drying process, trehalose dihydrate mainly formed an amorphous structure and acted as both cryoprotectant and lyoprotectant, while mannitol crystallized to serve as a bulking agent. The enzyme activities of Taq and 5 × HS-Taq Mix samples were measured via real-time quantitative PCR (qPCR). Long-term storage stability test demonstrated that freeze-dried samples with optimized formulations showed no remarkable reduction in amplification efficiencies for target sequence compared to freshly prepared corresponding samples after being stored at 37°C and 55% relative humidity (RH) for 0, 1, 4, 8 and 12 weeks.
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http://dx.doi.org/10.1016/j.xphs.2024.12.022 | DOI Listing |
Int J Mol Sci
December 2024
LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Cancer is a leading cause of death, so continuous efforts into cancer therapy are imperative. In tumor cells, telomerase and oncogene activity are key points for uncontrolled cell growth. Targeting these processes with ligands that inhibit telomerase and/or reduce oncogene expression has been identified as a promising cancer therapy.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Chemical Engineering, Polytechnic School, University of São Paulo, Av. Prof. Luciano Gualberto, Travessa 3, n. 380., São Paulo, SP, CEP 05508-900, Brazil.
16S ribosomal nucleic acid (16S rRNA) analysis allows to specifically target the metabolically active members of microbial communities. The stability of the ratios between target genes in the workflow, which is essential for the bioprocess-relevance of the data derived from this analysis, was investigated using synthetic mock communities constructed by mixing purified 16S rRNA from Bacillus subtilis (Bs), Staphylococcus aureus (Sa), Pseudomonas aeruginosa (Pa), Klebsiella pneumoniae (Kp) and Burkholderia cepacia (Bc) in different proportions. The RT reaction yielded one copy of cDNA per rRNA molecule for Pa, Bc and Sa but only 2/3 of the expected cDNA from 16S rRNAs of Bs and Kp.
View Article and Find Full Text PDFJ Pharm Sci
December 2024
Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Jiangsu Key Laboratory of Marine Biological Resources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungang 222005, China. Electronic address:
Polymerase chain reactions (PCR) are most reliable and precise means for nucleic acid analysis of biological samples. A cold-chain system with temperature at around -20°C is generally necessary for storage and transportation of PCR-related reagents. In order to facilitate ambient temperature storage and transportation, this study prepared Taq DNA polymerase and 5 × HS-Taq Mix (as low as 0.
View Article and Find Full Text PDFSci Justice
November 2024
Forensic Research Institute, Liverpool John Moores University, Byrom Street, Liverpool, UK; School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK.
The absence of a standardised method to quantify canine DNA recovered from livestock attacks leaves forensic providers without an important quality control step to help support their decision making. Typically used to normalise the amount of DNA for STR amplification, modern forensic DNA quantification approaches use qPCR of target genes and can also include an Internal Positive Controls (IPC) to determine the presence of PCR inhibitors. The co-amplification of livestock DNA alongside canine DNA has meant that previously developed qPCR methods are not suitable for use so a standardised approach is needed.
View Article and Find Full Text PDFJ Transl Med
November 2024
Key Laboratory of Ultra-Weak Magnetic Field Measurement Technology, School of Instrumentation and Optoelectronic Engineering, Ministry of Education, Beihang University, Beijing, 100191, China.
Background: With the increasing incidence of breast lesions, the differential diagnosis between benign lesions and breast cancer (BCa) has become a big challenge. Host peripheral blood mononuclear cells (PBMCs) could undergo changes in DNA methylation upon disease progression. However, the clinical value of DNA methylation of PBMCs in differentiating benign lesions and BCa is still unclear.
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