Objective To detect traces of microRNAs (miRNAs) in plasma and assess the expression stability of two common reference genes by stem-loop and poly A polymerase (PAP) real-time quantitative polymerase chain reaction (PCR) method, as miRNAs are the new bio-markers of tumor diagnosis and molecular targeted therapy, and its quantitative research is very important. Methods We extracted miRNAs from plasma of adult Sprague Dawley (SD) rats’ plasma, and detected the expressions of rno-miR-200b-3p and rno-miR-126-3p with stem-loop and PAP real-time PCR quantitative method, with rno-miR-103a-3p and U6 as internal controls. All the results were evaluated by 2△Ct method. Results Compared with PAP method, the stem-loop method reduced Ct value by 2-4 cycles and improved sensitivity by 10 times. In PAP method, the melting curve showed two peaks, a main peak and a small non-specific peak. Yet the melting curve of stem-loop method demonstrated a single specific peak. Furthermore, we validated the stability of internal references in the two real time PCR methods. U6 presented a more stable Ct value than rno-miR-103 in adult SD rats’ plasma samples. Conclusions Stem-loop real-time PCR is recommended as a major way to detect some samples with a low concentration of miRNAs, owing to its high accuracy and sensitivity. However, if a large number of tissue samples is going to be detected, PAP real-time PCR is more suitable and convenient than stem-loop method. U6 is more stable and repeatable than rno-miR-103a-3p as the reference gene to evaluate the semi-quantitative consequence of miRNAs.
ObjectiveTo compare four different transfection reagents for transfection efficiency of rat heart myoblast cells H9C2, to choose the optimal transfection method.MethodsThe plasmids of enhanced green fluorescent protein (EGFP) gene were transfected as exogenous genes to H9C2 cells from four different transfection regents including FuGENE HD, DNA-In CRISPR, Lipofectamine 3000 and Lipofectamine 2000. Fluorescence intensity was measured by fluorescence microscopy and fluorescence microplate reader to evaluate transfection efficiency. The effects of four transfection reagents on cell viability were measured by Cell Counting Kit-8 (CCK-8) reagents.ResultsTransfection efficiency of Lipofectamine 3000 was the highest (>50%), while that of DNA-In CRISPR was the lowest (<1%). The cytotoxicity of Lipofectamine 3000 was the lowest in the four transfection reagents and the cell viability was 94.55% after 48-hour transfection.ConclusionTransfection regent Lipofectamine 3000 has the relatively high transfection efficiency as well as the lowest cytotoxicity, which is more suitable for use in H9C2 cells by transfection.
ObjectiveTo construct a luciferase reporter fusion containing the human connective tissue growth factor (CTGF) gene promoter.MethodsThe promoter region of the human CTGF gene (-835/+214) was amplified by polymerase chain reaction (PCR) using specially-designed primers, and subsequently cloned into the pGL3.0-Basic vector. Following screening and verification by single colony PCR, double digestion, and sequencing, the resulting pGL3.0-Basic-CTGF was used to transfect the human embryonic kidney cells 293T, human bronchial epithelial cells HBE and human lung epithelial cells A549, and its function in each cell line was determined by luciferase assay.ResultsSequence alignment showed 99.5% identity, suggesting successful construction of the pGL3.0-Basic-CTGF reporter fusion. Promoter activities were detected 48 hours after transfection of pGL3.0-Basic-CTGF into the 293T, HBE, and A549 cells, and the promoter activities were 2.416, 0.027, and 0.121, respectively (P<0.01). Moreover, the luciferase activity in the A549 cells was statistically higher than that in the HBE cells (P<0.01).ConclusionsThe human pGL3.0-Basic-CTGF luciferase reporter fusion has been successfully constructed. The construct exhibits promoter activity in the bronchial epithelial cells HBE and the lung epithelial cells A549, and can therefore serve as a useful tool for future research in transcriptional regulation.
This paper reviews the research progress on live-cell super-resolution fluorescence microscopy, discusses the current research status and hotspots in this field, and summarizes the technological application of super-resolution fluorescence microscopy for live-cell imaging. To date, this field has gained progress in numerous aspects. Specifically, the structured illumination microscopy, stimulated emission depletion microscopy, and the recently introduced minimal photon fluxes microscopy are the current research hotspots. According to the current progress in this field, future development trend is likely to be largely driven by artificial intelligence as well as advances in fluorescent probes and relevant labelling methods.