1.Plasmid DNA extraction by double magnetic beads method and its application.
Chunhan YU ; Hui SONG ; Wengang CAO ; Xiaowen XIAO ; Jun DU
Chinese Journal of Biotechnology 2023;39(11):4708-4717
Plasmids are the most commonly used gene carriers in the field of gene synthesis and sequencing. However, the main problems faced by traditional plasmid DNA extraction technology are low extraction throughput and high production cost, so they cannot meet the growing demand. In this study, a double-magnetic-bead method (DMBM) for plasmid extraction was developed based on the principle of plasmid extraction. The effects of the input of magnetic beads, the size of plasmid DNA fragments, and the volume of bacterial on plasmid DNA extraction were explored. In addition, the quality, throughput, and cost of plasmid DNA extraction were also compared between this technique and the commercial plasmid DNA extraction kits. The results showed that the DMBM can meet the needs of extracting plasmid DNA with different cell densities and fragment lengths. Moreover, the sensitivity and quality of plasmid extraction by the DMBM method were both superior to those of the centrifugal adsorption column method. In addition, this technique could be applied on a 96-channel automated nucleic acid extractor, resulting in higher purity of the extracted plasmid DNA, 80% reduction in extraction time, and 57.1% reduction in cost. It also reduces manual operations, achieving high-throughput and low-cost plasmid DNA extraction, thus may facilitate gene synthesis and sequencing.
Plasmids/genetics*
;
DNA/genetics*
;
Nucleic Acids
;
Genetic Techniques
;
Magnetic Phenomena
2.Retrospective analysis of cell-free fetal DNA prenatal testing of maternal peripheral blood.
Youhua WEI ; Rui WANG ; Meixia XI ; Li WEI ; Wenjuan ZHU ; Yan LIU
Chinese Journal of Medical Genetics 2023;40(8):933-938
OBJECTIVE:
To assess the value of non-invasive prenatal testing (NIPT) for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies, chromosomal microdeletions and microduplications using cell-free fetal DNA from peripheral blood samples of pregnant women.
METHODS:
A total of 15 237 pregnant women who had undergone NIPT testing at the Maternity and Child Health Care Hospital of Zaozhuang from February 2015 to December 2021 were enrolled in this study. For those with a high risk by NIPT, amniotic fluid samples were collected for G-banding chromosomal karyotyping analysis and chromosomal microarray analysis to verify the consistency of NIPT with results of prenatal diagnosis. All of the women were followed up by telephone for pregnancy outcomes.
RESULTS:
Among the 15 237 pregnant women, 266 (1.75%) were detected with a high risk for fetal chromosomal abnormality were detected. Among these, 79 (29.7%) were at a high risk for T21, 26 (9.77%) were at a high risk for T18, 9 (3.38%) were at a high risk for T13, 74 (27.82%) were at a high risk for sex chromosome aneuploidies, 12 (4.51%) were at a high risk for other autosomal aneuploidies, and 66 (24.81%) were at a high risk for chromosomal microdeletions or microduplications. 217 women had accepted invasive prenatal diagnosis and respectively 50, 13, 1, 25, 1 and 18 were confirmed with T21, T18, T13, sex chromosome aneuploidies, autosomal aneuploidies and microdeletions/microduplications, and the positive predictive values were 75.76%, 68.42%, 11.11%, 40.32%, 10% and 35.29%, respectively. For 13 042 women (85.59%), the outcome of pregnancy were successfully followed up. During the follow-up, one false negative case of T21 was discovered. No false positive cases for T13 and T18 were found.
CONCLUSION
NIPT has a sound performance for screening T13, T18 and T21, and is also valuable for screening other autosomal aneuploidies, sex chromosome aneuploidies and chromosomal microdeletions/microduplications.
Child
;
Female
;
Pregnancy
;
Humans
;
Retrospective Studies
;
Cell-Free Nucleic Acids
;
Chromosome Disorders/genetics*
;
Prenatal Diagnosis/methods*
;
Down Syndrome/genetics*
;
Sex Chromosome Aberrations
;
Trisomy 18 Syndrome/genetics*
;
Trisomy 13 Syndrome/diagnosis*
;
Aneuploidy
;
DNA/genetics*
;
Trisomy/genetics*
3.Advances in modification and delivery of nucleic acid drugs.
Junfeng WANG ; Manman TAN ; Ying WANG ; Xiangrui LIU ; Aifu LIN
Journal of Zhejiang University. Medical sciences 2023;52(4):417-428
Nucleic acid-based drugs, such as RNA and DNA drugs, exert their effects at the genetic level. Currently, widely utilized nucleic acid-based drugs include nucleic acid aptamers, antisense oligonucleotides, mRNA, miRNA, siRNA and saRNA. However, these drugs frequently encounter challenges during clinical application, such as poor stability, weak targeting specificity, and difficulties in traversing physiological barriers. By employing chemical modifications of nucleic acid structures, it is possible to enhance the stability and targeting specificity of certain nucleic acid drugs within the body, thereby improving delivery efficiency and reducing immunogenicity. Moreover, utilizing nucleic acid drug carriers can facilitate the transportation of drugs to lesion sites, thereby aiding efficient intracellular escape and promoting drug efficacy within the body. Currently, commonly employed delivery carriers include virus vectors, lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, protein carriers and extracellular vesicles. Nevertheless, individual modifications or delivery carriers alone are insufficient to overcome numerous obstacles. The integration of nucleic acid chemical modifications with drug delivery systems holds promise for achieving enhanced therapeutic effects. However, this approach also presents increased technical complexity and clinical translation costs. Therefore, the development of nucleic acid drug carriers and nucleic acid chemical modifications that are both practical and simple, while maintaining high efficacy, low toxicity, and precise nucleic acid delivery, has become a prominent research focus in the field of nucleic acid drug development. This review comprehensively summarizes the advancements in nucleic acid-based drug modifica-tions and delivery systems. Additionally, strategies to enhance nucleic acid drug delivery efficiency are discussed, with the aim of providing valuable insights for the translational application of nucleic acid drugs.
Nucleic Acids
;
RNA, Small Interfering/genetics*
;
Drug Carriers
;
Drug Delivery Systems
;
Drug Development
4.Research progress in mitochondrial gene editing technology.
Yichen WANG ; Ying WANG ; Yu CHEN ; Qingfeng YAN ; Aifu LIN
Journal of Zhejiang University. Medical sciences 2023;52(4):460-472
Mitochondrial DNA (mtDNA) mutations result in a variety of genetic diseases. As an emerging therapeutic method, mtDNA editing technology recognizes targets more based on the protein and less on the nucleic acid. Although the protein recognition type mtDNA editing technology represented by zinc finger nuclease technology, transcription activator like effector nuclease technology and base editing technology has made some progress, the disadvantages of complex recognition sequence design hinder further popularization. Gene editing based on nucleic acid recognition by the CRISPR system shows superiority due to the simple structure, easy design and modification. However, the lack of effective means to deliver nucleic acids into mitochondria limits application in the field of mtDNA editing. With the advances in the study of endogenous and exogenous import pathways and the deepening understanding of DNA repair mechanisms, growing evidence shows the feasibility of nucleic acid delivery and the broad application prospects of nucleic acid recognition type mtDNA editing technology. Based on the classification of recognition elements, this article summarizes the current principles and development of mitochondrial gene editing technology, and discusses its application prospects.
Genes, Mitochondrial
;
Gene Editing
;
Mitochondria/genetics*
;
DNA, Mitochondrial/genetics*
;
Nucleic Acids
;
Technology
5.Related factors of negative conversion time of nucleic acid in children with COVID-19.
Yu Feng LI ; Jian Hua ZHANG ; Han GAN ; Kai Chuang ZHANG ; Kang CAI ; Wei LIU ; Sheng Nan LUO ; Hong Li JIANG ; Biao JIN ; Li Bin ZHAO ; Kun SUN
Chinese Journal of Pediatrics 2023;61(3):256-260
Objective: To explore the related factors of negative conversion time (NCT) of nucleic acid in children with COVID-19. Methods: A retrospective cohort study was conducted. A total of 225 children who were diagnosed with COVID-19 and admitted to Changxing Branch of Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from April 3rd to May 31st 2022 were enrolled in the study. The infection age, gender, viral load, basic disease, clinical symptoms and information of accompanying caregivers were retrospectively analyzed. According to age, the children were divided into<3 years of age group and 3-<18 years of age group. According to the viral nucleic acid test results, the children were divided into positive accompanying caregiver group and negative accompanying caregiver group. Comparisons between groups were performed using Mann-Whitney U test or Chi-square test. Multivariate Logistic regression analysis was used to analyze the related factors of NCT of nucleic acid in children with COVID-19. Results: Among the 225 patients (120 boys and 105 girls) of age 2.8 (1.3, 6.2) years, 119 children <3 years and 106 children 3-<18 years of age, 19 cases were diagnosed with moderate COVID-19, and the other 206 cases were diagnosed with mild COVID-19. There were 141 patients in the positive accompanying caregiver group and 84 patients in the negative accompanying caregiver group.Patients 3-<18 years of age had a shorter NCT (5 (3, 7) vs.7 (4, 9) d, Z=-4.17, P<0.001) compared with patients <3 years of age. Patients in the negative accompanying caregiver group had a shorter NCT (5 (3, 7) vs.6 (4, 9) d,Z=-2.89,P=0.004) compared with patients in the positive accompanying caregiver group. Multivariate Logistic regression analysis showed that anorexia was associated with NCT of nucleic acid (OR=3.74,95%CI 1.69-8.31, P=0.001). Conclusion: Accompanying caregiver with positive nucleic acid test may prolong NCT of nucleic acid, and decreased appetite may be associated with prolonged NCT of nucleic acid in children with COVID-19.
Adolescent
;
Child
;
Child, Preschool
;
Female
;
Humans
;
Male
;
Young Adult
;
China/epidemiology*
;
COVID-19/genetics*
;
Nucleic Acids
;
Retrospective Studies
6.CRISPR-based molecular diagnostics: a review.
Wenjun SUN ; Xingxu HUANG ; Xinjie WANG
Chinese Journal of Biotechnology 2023;39(1):60-73
Rapid and accurate detection technologies are crucial for disease prevention and control. In particular, the COVID-19 pandemic has posed a great threat to our society, highlighting the importance of rapid and highly sensitive detection techniques. In recent years, CRISPR/Cas-based gene editing technique has brought revolutionary advances in biotechnology. Due to its fast, accurate, sensitive, and cost-effective characteristics, the CRISPR-based nucleic acid detection technology is revolutionizing molecular diagnosis. CRISPR-based diagnostics has been applied in many fields, such as detection of infectious diseases, genetic diseases, cancer mutation, and food safety. This review summarized the advances in CRISPR-based nucleic acid detection systems and its applications. Perspectives on intelligent diagnostics with CRISPR-based nucleic acid detection and artificial intelligence were also provided.
Humans
;
CRISPR-Cas Systems/genetics*
;
COVID-19/genetics*
;
Pandemics
;
Artificial Intelligence
;
Nucleic Acids
7.Multiomics and Multidimensional Testing for Efficacy Monitoring of Patients with Lymphoma.
Xin-Hua WANG ; Yan-Xin YANG ; Ying-Jun WANG ; Bao-Hong YUE ; Ming-Zhi ZHANG
Journal of Experimental Hematology 2023;31(3):746-752
OBJECTIVE:
To explore the role of a new blood-based, multiomics and multidimensional method for evaluating the efficacy of patients with lymphoma.
METHODS:
10 ml peripheral blood was extracted from each patient, and the genomic copy number aberrations (CNA) and fragment size (FS) were evaluated by low-depth whole genome sequencing of cfDNA, and the level of a group of plasma tumor marker (PTM) were detected at the same time. The cancer efficacy score (CES) was obtained by standardized transformation of the value of above three numerical indexes, and the changes of CES before and after treatment were compared to evaluate the patient's response to the treatment regimen.
RESULTS:
A total of 35 patients' baseline data were collected, of which 23 cases (65.7%) had elevated CES values. 18 patients underwent the first time test. The results showed that the CES value of 9 patients with positive baseline CES decreased significantly at the first test, and the efficacy evaluation was PR, which was highly consistent with the imaging evaluation results of the same period. At the same time, the CNA variation spectrum of all patients were evaluated and it was found that 23 patients had partial amplification or deletion of chromosome fragments. The most common amplification site was 8q24.21, which contains important oncogenes such as MYC. The most common deletion sites were 1p36.32, 4q21.23, 6q21, 6q27, 14q32.33, and tumor suppressor-related genes such as PRDM1, ATG5, AIM1, FOXO3 and HACE1 were expressed in the above regions, so these deletions may be related to the occurrence and development of lymphoma.
CONCLUSION
With the advantages of more convenience, sensitivity and non-invasive, this multiomics and multidimensional efficacy detection method can evaluate the tumor load of patients with lymphoma at the molecular level, and make more accurate efficacy evaluation, which is expected to serve the clinic better.
Humans
;
Multiomics
;
Lymphoma/genetics*
;
Cell-Free Nucleic Acids
;
Genomics/methods*
;
DNA Copy Number Variations
;
Ubiquitin-Protein Ligases
8.The value of re-sampling for patients who had failed non-invasive prenatal testing due to low cell-free fetal DNA fraction.
Ganye ZHAO ; Peng DAI ; Shanshan GAO ; Conghui WANG ; Xuechao ZHAO ; Lina LIU ; Xiangdong KONG
Chinese Journal of Medical Genetics 2022;39(2):135-138
OBJECTIVE:
To assess the value of re-sampling for patients who had failed non-invasive prenatal testing (NIPT) due to low cell-free fetal DNA (cffDNA) fraction.
METHODS:
Clinical data of 20 387 patients undergoing NIPT test was reviewed. The patients were re-sampled when initial blood test did not yield a result due to cffDNA fraction. The results were analyzed, and the outcome of pregnancy was followed up.
RESULTS:
Among all samples, 17 (0.08%) had failed to yield a result due to low cffDNA fraction, all of which accepted re-sampling. A result was attained in 16 cases, with a success rate of 94.12%. Only one sample had failed the re-test.
CONCLUSION
For patients who had failed the initial NIPT due to low cffDNA fraction, re-sampling should be considered with gestational week and ultrasound results taken into consideration.
Aneuploidy
;
Cell-Free Nucleic Acids/genetics*
;
DNA/genetics*
;
Female
;
Fetus
;
Humans
;
Pregnancy
;
Prenatal Diagnosis
9.Practice of clinical application of noninvasive prenatal testing based on cell-free fetal DNA.
Honglei DUAN ; Wanjun WANG ; Ying ZHANG ; Wei LIU ; Leilei GU ; Jie LI
Chinese Journal of Medical Genetics 2022;39(3):264-268
OBJECTIVE:
To assess the application value of noninvasive prenatal testing (NIPT) based on cell-free fetal DNA.
METHODS:
The results of 2777 cases of basic and extended NIPT were retrospectively analyzed. The clinical data and outcome of pregnancy were analyzed, in addition with the diagnosis rate and testing efficiency.
RESULTS:
Among the 2777 pregnant women, 1192 (42.9%) had accepted basic NIPT and 1585 (57.1%) accepted extended NIPT. With a failure rate of 0.1%, 8 and 6 cases were reported respectively as high-risk pregnancies for trisomy 21 and sex chromosomal abnormalities. Other genetic abnormalities were detected in 32 cases. The positive predictive value for trisomy 21 was 85.7%, and one case of 47,XXX was diagnosed among 3 women with high risks for sex chromosomal abnormalities. For those with a high risk for other genetic abnormalities, pregnant diagnosis rates of basic and extended NIPT were 71.4% (5/7) and 68.2% (15/22), respectively. Seven copy number variations (CNVs) were confirmed, including one pathogenic CNV, one likely pathogenic CNV and 5 variants of unknown significance. Among 6 cases with high-risk of maternal CNVs, 5 fetuses and the mothers were confirmed to be carriers. No CNV was detected in the remainder fetus by chromosomal microarray analysis, while its mother was a carrier of the corresponding CNV.
CONCLUSION
NIPT has shown a relatively high positive predictive value for the screening of trisomy 21 and maternal CNVs but with a limited efficiency for the discovery of fetal CNVs. For other genetic abnormalities signaled by NIPT, informed choice by the pregnant women during pre-testing consultation is recommended. Invasive prenatal diagnosis should be considered in the combination of NIPT reports and fetal ultrasound, while the residual risks should be fully informed.
Aneuploidy
;
Cell-Free Nucleic Acids/genetics*
;
DNA/genetics*
;
DNA Copy Number Variations
;
Female
;
Fetus
;
Humans
;
Noninvasive Prenatal Testing
;
Pregnancy
;
Retrospective Studies
10.Consistency analysis and clinical guiding significance of cytomegalovirus nucleic acid and antibody detections in patients with different clinical characteristics.
Ju Hua DAI ; Xin Ping SUN ; Jie ZHANG ; Lian Jie SHI
Journal of Peking University(Health Sciences) 2022;54(2):267-271
OBJECTIVE:
To investigate the consistency of cytomegalovirus deoxyribo nucleic acid (CMV-DNA) and immunoglobulin M (IgM) antibody detections in patients with different clinical characteristics and their guiding value for clinical practice.
METHODS:
From December 2014 to November 2019, a total of 507 patients who were detected with both CMV-IgM and CMV-DNA were collected in Peking University International Hospital. Their general information, such as gender, age and clinical data, including the patient's diagnosis, medication, and outcome were also collected. The groups were stratified according to whether CMV-DNA was negative or positive, CMV-IgM was negative or positive, age, gender, and whether they received immunosuppressive therapy or not. The Pearson Chi-square test or Fisher's exact test was used for comparison of the rates between the groups. P < 0.05 means the difference is statisti-cally significant.
RESULTS:
Of the 507 patients submitted for examination, 55 (10.85%) were positive for CMV-DNA, 74 (14.60%) were positive for CMV-IgM, and 20 (3.94%) were positive for both CMV-DNA and CMV-IgM. Of the 55 patients with CMV-DNA positive, 37 were male, accounting for 67.27%. In addition, 25 patients were older than 60 years, accounting for 45.45% and 33 patients received immunosuppressive therapy, accounting for 60%. The rates were higher than that of CMV-DNA negative group, 47.35% (P=0.005), 68.14% (P=0.043), 46.02% (P=0.050), respectively. Of the patients with both CMV-DNA and IgM positive, 45% received immunosuppressive threapy, which was lower than that of CMV-DNA positive but IgM negative patients (68.57%, P=0.086), and also lower than CMV-DNA negative but IgM positive patients (68.52%, P=0.064). In the patients with both CMV-DNA and IgM positive, 91.67% showed remission after receiving ganciclovir, whereas in the patients with CMV-DNA positive but IgM negative, the rate was only 60% (P=0.067).
CONCLUSION
CMV-IgM antibody detection is affected by age, gender, and immune status. It is not recommended to use CMV-IgM alone to determine CMV infection in patients with immunosuppressive status and those older than 60 years. CMV-DNA and CMV-IgM combined detection may help to predict patients' immune status and outcomes of antiviral therapy.
Antibodies, Viral
;
Cytomegalovirus/genetics*
;
Cytomegalovirus Infections/drug therapy*
;
DNA
;
Female
;
Humans
;
Immunoglobulin M
;
Immunosuppressive Agents/therapeutic use*
;
Male
;
Nucleic Acids

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