Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (579 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
The uptake of naked or purified DNA by cells, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (transformation, bacterial) and both are routinely employed in gene transfer techniques.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Transfections.
Where it fits in the MeSH classification
- Broader topics
- Gene Transfer Techniques; Recombination, Genetic
- Narrower topics
- Transformation, Bacterial
- See also
- Transformation, Bacterial; Transformation, Genetic; Electroporation
Related concepts
- Cells
- Transformation
- Bacterial
- Gene Transfer Techniques
Research landscape
PubMed indexes 155,053 records tagged with the MeSH heading “Transfection” (counts retrieved 2026-10-29). 5,399 of them (3.5%) were published from 2020 onward, and the busiest period so far is 2000-2009 with 64,927 records.
Reviews account for 2,957 records (1.9%) and meta-analyses for 32. Randomized controlled trials number 60 (0.0%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 47,534 |
| 2000-2009 | 64,927 |
| 2010-2019 | 37,193 |
| 2020 onward | 5,399 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 2,957 | 1.9% |
| Meta-analyses | 32 | 0.0% |
| Randomized controlled trials | 60 | 0.0% |
Method: PubMed query "Transfection"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in genetics and genomics
Genetic findings vary widely in strength. A variant linked to a condition in one study may not replicate in other ancestries, and most common variants have small effects that are meaningful only in aggregate. Studies of rare, high-impact variants can support strong causal claims about a gene, while association studies describe statistical links that need functional and independent replication. Check the sample size, the ancestry of participants, whether results were replicated, and whether a laboratory or clinical outcome was actually measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Systematic Screening of Commonly Used Commercial Transfection Reagents towards Efficient Transfection of Single-Stranded Oligonucleotides | 2018 | Research article Design not recorded in structured metadata | 159 | cc by PMID 30297632 · DOI · PMC6222501 |
| Competence in Streptococcus pneumoniae and Close Commensal Relatives: Mechanisms and Implications | 2019 | Review article Design not recorded in structured metadata | 96 | cc by PMID 31001492 · DOI · PMC6456647 |
| The circadian clock and darkness control natural competence in cyanobacteria | 2020 | Research article Design not recorded in structured metadata | 92 | cc by PMID 32245943 · DOI · PMC7125226 |
| Reversible DNA condensation drives natural transformation | 2026 | Research article Design not recorded in structured metadata | 1 | cc by PMID 41857013 · DOI · PMC13168374 |
Systematic Screening of Commonly Used Commercial Transfection Reagents towards Efficient Transfection of Single-Stranded Oligonucleotides [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Non-viral vector-mediated transfection is a core technique for in vitro screening of oligonucleotides.
- Closing excerpt
- We firmly believe that our findings may contribute to the future In vitro delivery and screening of single-stranded therapeutic oligonucleotides such as antisense oligonucleotides, antimiRs, and DNAzymes.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (179 words)
Non-viral vector-mediated transfection is a core technique for in vitro screening of oligonucleotides. Despite the growing interests in the development of oliogonucleotide-based drug molecules in recent years, a comprehensive comparison of the transfection efficacy of commonly used commercial transfection reagents has not been reported. In this study, five commonly used transfection reagents, including Lipofectamine 3000, Lipofectamine 2000, Fugene, RNAiMAX and Lipofectin, were comprehensively analyzed in ten cell lines using a fluorescence imaging-based transfection assay. Although the transfection efficacy and toxicity of transfection reagents varied depending on cell types, the toxicity of transfection reagents generally displayed a positive correlation with their transfection efficacy. According to our results, Lipofectamine 3000, Fugene and RNAiMAX showed high transfection efficacy, however, RNAiMAX may be a better option for majority of cells when lower toxicity is desired. The transfection efficacy of Lipofectamine 2000 was compromised by its high toxicity, which may adversely affect its application in most cells. We firmly believe that our findings may contribute to the future In vitro delivery and screening of single-stranded therapeutic oligonucleotides such as antisense oligonucleotides, antimiRs, and DNAzymes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 30297632 · DOI · PMC6222501
Competence in Streptococcus pneumoniae and Close Commensal Relatives: Mechanisms and Implications [2]
Abstract reading summary — source excerpts
- Opening excerpt
- The mitis group of streptococci comprises species that are common colonizers of the naso-oral-pharyngeal tract of humans.
- Closing excerpt
- Here, we explore the general mechanism of natural genetic transformation in the two species and touch upon the fundamental clinical and evolutionary implications of sharing similar competence, fratricide mechanisms, and a large fraction of their genomic DNA.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (141 words)
The mitis group of streptococci comprises species that are common colonizers of the naso-oral-pharyngeal tract of humans. Streptococcus pneumoniae and Streptococcus mitis are close relatives and share ~60-80% of orthologous genes, but still present striking differences in pathogenic potential toward the human host. S. mitis has long been recognized as a reservoir of antibiotic resistance genes for S. pneumoniae, as well as a source for capsule polysaccharide variation, leading to resistance and vaccine escape. Both species share the ability to become naturally competent, and in this context, competence-associated killing mechanisms such as fratricide are thought to play an important role in interspecies gene exchange. Here, we explore the general mechanism of natural genetic transformation in the two species and touch upon the fundamental clinical and evolutionary implications of sharing similar competence, fratricide mechanisms, and a large fraction of their genomic DNA.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 31001492 · DOI · PMC6456647
The circadian clock and darkness control natural competence in cyanobacteria [3]
Abstract reading summary — source excerpts
- Opening excerpt
- The cyanobacterium Synechococcus elongatus is a model organism for the study of circadian rhythms.
- Closing excerpt
- Thus, the competence state in cyanobacteria is regulated by the circadian clock and can adapt to seasonal changes of day length.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (114 words)
The cyanobacterium Synechococcus elongatus is a model organism for the study of circadian rhythms. It is naturally competent for transformation-that is, it takes up DNA from the environment, but the underlying mechanisms are unclear. Here, we use a genome-wide screen to identify genes required for natural transformation in S. elongatus, including genes encoding a conserved Type IV pilus, genes known to be associated with competence in other bacteria, and others. Pilus biogenesis occurs daily in the morning, while natural transformation is maximal when the onset of darkness coincides with the dusk circadian peak. Thus, the competence state in cyanobacteria is regulated by the circadian clock and can adapt to seasonal changes of day length.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 32245943 · DOI · PMC7125226
Reversible DNA condensation drives natural transformation [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Natural transformation drives the spread of antibiotic resistance among bacteria.
- Closing excerpt
- Our results show that ComEA reversibly condenses DNA during natural transformation, first producing force to pull DNA into the periplasm and then abating force production to promote transport into the cytoplasm.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (145 words)
Natural transformation drives the spread of antibiotic resistance among bacteria. The DNA receptor ComEA is essential for transporting external transforming DNA into the periplasm by an unknown mechanism. Here, single-molecule optical tweezers and electron microscopy approaches show that Geobacillus stearothermophilus ComEA forms dynamic oligomers on DNA that can switch between two conformations depending on local concentration. When ComEA sparsely decorates DNA, it forms bridging oligomers that condense the DNA to generate sub-pN pulling forces. When ComEA more fully decorates DNA, it forms non-bridging oligomers that decondense DNA and cannot generate force. Mutating ComEA to favor either bridging or non-bridging conformations causes transformation deficiency in Bacillus subtilis, meaning condensation and decondensation each play mechanistic roles. Our results show that ComEA reversibly condenses DNA during natural transformation, first producing force to pull DNA into the periplasm and then abating force production to promote transport into the cytoplasm.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41857013 · DOI · PMC13168374
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Production of recombinant protein therapeutics in cultivated mammalian cells [5]
- Research article Synthetic DNA delivery systems [6]
- Research article Uptake pathways and subsequent intracellular trafficking in nonviral gene delivery [7]
- Research article In vitro and ex vivo strategies for intracellular delivery [8]
- Research article Bacterial gene transfer by natural genetic transformation in the environment [9]
- Research article Gene therapy progress and prospects: nonviral vectors [10]
References
- Wang T, Larcher LM, Ma L, Veedu RN. Systematic Screening of Commonly Used Commercial Transfection Reagents towards Efficient Transfection of Single-Stranded Oligonucleotides. . 2018. PMID 30297632 · DOI · PMC6222501
- Salvadori G, Junges R, Morrison DA, Petersen FC. Competence in Streptococcus pneumoniae and Close Commensal Relatives: Mechanisms and Implications. . 2019. PMID 31001492 · DOI · PMC6456647
- Taton A, Erikson C, Yang Y, Rubin BE, Rifkin SA, Golden JW, et al.. The circadian clock and darkness control natural competence in cyanobacteria. . 2020. PMID 32245943 · DOI · PMC7125226
- Santiago JI, Ahmed I, Hahn J, Rubino A, Choi H, Adami G, et al.. Reversible DNA condensation drives natural transformation. . 2026. PMID 41857013 · DOI · PMC13168374
- Wurm FM. Production of recombinant protein therapeutics in cultivated mammalian cells. Nat Biotechnol. 2004. PMID 15529164 · DOI
- Luo D, Saltzman WM. Synthetic DNA delivery systems. Nat Biotechnol. 2000. PMID 10625387 · DOI
- Khalil IA, Kogure K, Akita H, Harashima H. Uptake pathways and subsequent intracellular trafficking in nonviral gene delivery. Pharmacol Rev. 2006. PMID 16507881 · DOI
- Stewart MP, Sharei A, Ding X, Sahay G, Langer R, Jensen KF. In vitro and ex vivo strategies for intracellular delivery. Nature. 2016. PMID 27734871 · DOI
- Lorenz MG, Wackernagel W. Bacterial gene transfer by natural genetic transformation in the environment. Microbiol Rev. 1994. PMID 7968924 · DOI · PMC372978
- Niidome T, Huang L. Gene therapy progress and prospects: nonviral vectors. Gene Ther. 2002. PMID 12457277 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.