Yanni Lin, TJ Cradick, Gang Bao and colleagues from Georgia Tech and Emory reported recently in Nucleic Acids Research on how the CRISPR/Cas9 gene editing system can sometimes miss its mark.
CRISPR/Cas9 has received abundant coverageÂ fromÂ science-focused mediaÂ outlets.Â Basically, it is a convenient system for cutting DNA in cells in a precise way. This paper shows that the CRISPR/Cas9 system can sometimes cut DNA in places that donâ€™t exactly match the designed target.
Here we show that CRISPR/Cas9 systems can have off-target cleavage when DNA sequences have an extra base or a missing base at various locations compared with the corresponding RNA guide strandâ€¦Our results suggest the need to perform comprehensive off-target analysis by considering cleavage due to DNA and sgRNA bulges in addition to base mismatches.
CRISPR/Cas9 could be used to develop therapies for humans for genetic blood diseases such as sickle cell or thalassemia, and this paper does not change that potential. But the authors are cautioning fellow scientists that they need to design their tools carefully and perform quality control. Other investigators have made similarÂ findings.
Pure cardiac muscle cells, ready to transplant into a patient affected by heart disease.
Thatâ€™s a goal for many cardiology researchers working with stem cells. Having a pure population of cardiac muscle cells is essential for avoiding tumor formation after transplantation, but has been technically challenging.
Fluorescent beacons that distinguish cardiac muscle cells
Researchers at Emory and Georgia Tech have developed a method for Cheap Oakleys purifying cardiac muscle cells from stem cell cultures using molecular beacons.
Molecular beacons are tiny “instruments” that become fluorescent only when they find cells that have turned on certain genes. In this case, they target instructions to make a type of myosin, a protein found in cardiac muscle cells.
Doctors could use purified cardiac muscle cells to heal damaged areas of the heart in patients affected by heart attack and heart failure. In addition, the molecular beacons technique http://www.lependart.com could have broad applications across regenerative medicine, because it could be used with other types of cells produced from stem cell cultures, such as brain cells or insulin-producing islet cells.
The results are published in the journal Circulation.
“Often, we want to generate a particular cell population from stem cells for introduction into patients,” says co-senior author Young-sup Yoon, MD, PhD, professor of medicine (cardiology) and director of stem cell biology at Emory University School of Medicine. “But the desired cells often lack a readily accessible surface marker, or that marker is not specific enough, as is the case for cardiac muscle cells. This technique could allow us to purify almost any type of cell.”