We have recently developed an in vitro assay for human tumor stem cells that permits cloning of human ovarian adenocarcinoma cells in soft agar. Tumor colonies grew from both effusions and biopsies from 85% of 31 ovarian cancer patients. The cloning efficiency did not vary with the histology of the tumor. Growth was induced with medium conditioned by the adherent spleen cells of mineral oil-pri...

Large-scale production of biopharmaceuticals by current bioreactor techniques is limited by low transgenic efficiency and low expression of foreign proteins. In general, a bacterial artificial chromosome (BAC) harboring most regulatory elements is capable of overcoming the limitations, but transferring BAC into donor cells is difficult. We describe here the use of cattle mammary bioreactor to p...

A variety of methods have been developed for cloning PCR products, including blunt-end cloning (1), restriction cut back (2), ligation-independent cloning (3), uracil DNA–glycosylase (UDG) treatment of uracil-containing deoxyoligonucleotide primers (4,5) and TA cloning (6–8). Blunt-end cloning of PCR products often requires treatment of PCR products to polish the ends (9). Even with treatments,...

Xist is an X-linked gene responsible for cis induction of X chromosome inactivation. Studies have indicated that Xist is abnormally activated in the active X chromosome in cloned mouse embryos due to loss of the maternal Xist-repressing imprint following enucleation during somatic cell nuclear transfer (SCNT). Inhibition of Xist expression by injecting small interfering RNA (siRNA) has been sho...

Synthetic biology builds upon the foundation of engineering principles, prompting innovation and improvement in biotechnology via a design-build-test-learn cycle. A community-wide standard in DNA assembly would enable bio-molecular engineering at the levels of predictivity and universality in design and construction that are comparable to other engineering fields. Golden Gate Assembly technolog...

BACKGROUND RNA interference (RNAi) is a conserved gene silencing mechanism mediated by small inhibitory microRNAs (miRNAs).Promoter-driven miRNA expression vectors have emerged as important tools for delivering natural or artificially designed miRNAs to eukaryotic cells and organisms. Such systems can be used to query the normal or pathogenic functions of natural miRNAs or messenger RNAs, or to...

Somatic cloning, also known as somatic cell nuclear transfer (SCNT), is a promising technology which has been expected to rapidly extend the population of elaborately selected breeding boars with superior production performance. Chinese Guike No. 1 pig breed is a novel swine specialized strain incorporated with the pedigree background of Duroc and Chinese Luchuan pig breeds, thus inherits an ex...

Molecular cloning methods based on primer and overlap extension PCR are widely used due to their simplicity, reliability,low cost and high efficiency. In this article, an efficient mega primer (MP)-mediated cloning strategy for chimeragenesis and long DNA fragment insertion is presented. MP cloning is a seamless, restriction/ligation-independent method that requires only three steps: i) the fir...