"Unlocking Photostable Monomers by Splitting StayGold Dimer"

In a groundbreaking advancement in the field of fluorescent proteins, researchers have successfully monomerized the highly photostable StayGold dimer, leading to the creation of three distinct monomeric variants. StayGold, known for its exceptional photostability, has long been a game-changer in live-cell imaging applications.

The discovery of StayGold as an obligate dimer posed challenges in various applications such as protein tagging and biosensor engineering. To address this, researchers embarked on the task of evolving monomeric variants from the dimeric StayGold. Through targeted mutagenesis and structural analysis, three independent research teams were able to generate monomeric variants named mStayGold, StayGold-E138D, and mBaoJin.

The researchers utilized sophisticated techniques, including crystal structure analysis and mutagenesis, to disrupt the dimerization interface of StayGold effectively. The resulting monomeric variants exhibited impressive qualities, with mStayGold standing out as the most suitable for a wide range of applications due to its brightness, photostability, and monomeric nature. StayGold-E138D and mBaoJin also showcased unique properties, offering researchers additional options for their experiments.

The comparison of these monomeric variants in standard mammalian cell lines revealed mStayGold as the top performer across critical parameters. However, the suitability of fluorescent proteins can vary depending on the biological system and experimental setup, emphasizing the importance of thorough evaluation before use.

The precise mechanism behind StayGold's remarkable photostability remains a subject of ongoing research. The presence of a chloride ion near the chromophore in the crystal structure hints at a potential protective role, although further investigation is required to fully understand this phenomenon.

Overall, the development of monomeric StayGold variants marks a significant leap forward in biological imaging, promising new avenues for research and applications in the field. As scientists continue to explore the capabilities of these innovative probes, collaboration and data sharing within the scientific community are essential for maximizing their potential.

Source: [Nature Methods](https://www.nature.com/articles/s41592-024-02223-8)