For Research Use Only. Not for Clinical Use.

With the development of fluorescent protein label research, a series of fluorescent protein tags with special features were discovered and applied in the half-life area. Among them, bleach-chase technology has the most extensive application prospect as a creative half-life assay method which does not require translation inhibitors, antibodies, or radioactive labeling. After decades of application, bleach-chase tend to be increasingly mature and generally accepted in protein drug field. Creative Biolabs is an outstanding service provider who offers the most comprehensive and professional bleach-chase based half-life assay service to advance clients' projects.

Introduction of Half-life Assay by Bleach-chase

Using mammalian cells to measure protein drugs half-life in vitro generally suffers from a fact that cells remove proteins by two main processes: intracellular degradation and dilution. The former one usually acts as the most important role in the protein drugs degradation in vivo via the protease and proteasome, namely endogenous degradation, while the dilution of therapeutic proteins with cell growth reduces the protein amount by 50% with every division. However, this dilution process occurs mainly in the proteins half-life assay in vitro, which interferes the estimation of true half-life in vivo. Nowadays, the emergence of bleach-chase technology solved this problem by separating the above two protein removal processes.

As a novel and elegant half-life assay approach, bleach-chase technology depends on the fact that a brief pulse of light renders a fluorescent tag non-fluorescent, in an irreversible manner. In this case, the protein removal or disappearance rate is tracked as the difference between bleached and unbleached protein fluorescence, while the rate of degradation is related to the rate of post-bleaching fluorescence recovery, which can further calculate the half-life of target proteins.

Fig.1 Sketch of Bleach-chase. (Eldeeb, 2019)

Fig.2 Bleach-chase workflow. (Eden, 2011)

Applications of Half-life Assay by Bleach-chase

Bleach-chase technology can be applied to multiple proteins and time points in living cells and is generally applicable to fluorescently tagged proteins. Moreover, this method is suitable for high throughput determination of protein half-lives, which provides convenience to the screening of candidate protein drugs based on their pharmacokinetic properties.

In recent years many groups determined the proteins half-lives in a variety of cells by bleach-chase, especially in cancer related research. Some researchers measured endogenous proteins' half-life in cancer cells by this approach and compared different proteins' half-life variation under the presence of chemotherapeutic drugs, and recent methodologies may help in elucidating how the cell dynamically controls its proteome.

Highlights of Half-life Assay by Bleach-chase

• High throughput and short time.
• Closer to true half-life in vivo.
• Conveniently and rapidly.
• General suitable to most proteins.

As a novel and creative method to assay proteins' half-life, bleach-chase technology has been widely spread in therapeutic protein development field. If you are interested in our half-life assay service by bleach-chase, please feel free to contact us.

References

1. Eldeeb, E. A.; et al. A molecular toolbox for studying protein degradation in mammalian cells. Journal of neurochemistry. 2019, 151(4), 520-533.
2. Eden, E.; et al. Proteome half-life dynamics in living human cells. Science. 2011, 331(6018), 764-768.