Potassium simplex optimized medium
Potassium Simplex Optimized Medium (KSOM) is a specialized medium primarily used for in vitro culture of mouse preimplantation embryos in research.[1][2]
Development
[edit]The culture of preimplantation embryos is of paramount importance as it serves as a foundation for exploring embryo development, advancing assisted reproductive technology, and facilitating the generation of genetically modified animals.[1] The primary motivation behind the establishment of KSOM was to address the phenomenon known as the two-cell block, wherein mouse embryos encounter developmental arrest at the two-cell stage.[3] Researchers Lawitts and Biggers, in their groundbreaking work in the early 1990s, employed a sequential simplex optimization strategy to solve this issue.[4] This method involves a systematic approach to optimize multiple variables simultaneously, allowing for the fine-tuning of media components. Their efforts culminated in the formulation of the Simplex Optimized Medium (SOM). Further refinements based on the intracellular K+/Na+ ratio in the two-cell stages led to the evolution of KSOM, potassium-supplemented SOM.[4] Because KSOM uses a bicarbonate buffering mechanism, it is dependent on a CO2 incubator to maintain the right pH. The handling of embryos outside a CO2 incubator necessitates the use of HEPES buffered media, such as M2.[2]
Applications and advancements
[edit]Following the foundational success of KSOM, researchers sought to further enhance the mediums' efficacy. This led to the introduction of amino acid supplementation, resulting in the variant known as KSOM/AA. The availability of amino acids in the medium further aided in the development of mouse embryos and augmented their growth potential.[5] KSOM/AA has ever since become the most widely used medium for the culture of preimplantation mouse embryos in research.[2][1] Ready-to-use KSOM/AA can be obtained from various commercial vendors but it can also be prepared in-house based on published protocols.[2]
See also
[edit]References
[edit]- ^ a b c Summers, Michael C. (2013-09-18). "A brief history of the development of the KSOM family of media". Journal of Assisted Reproduction and Genetics. 30 (8): 995–999. doi:10.1007/s10815-013-0097-8. ISSN 1058-0468. PMC 3790120. PMID 24046024.
- ^ a b c d Behringer, Richard, ed. (2014). Manipulating the mouse embryo: a laboratory manual (4th ed.). Cold Spring Harbor, NY: CSH, Cold Spring Harbor Laboratory Pr. ISBN 978-1-936113-01-9.
- ^ Goddard, Martin J.; Pratt, Hester P. M. (1983-02-01). "Control of events during early cleavage of the mouse embryo: an analysis of the '2-cell block'". Development. 73 (1): 111–133. doi:10.1242/dev.73.1.111. ISSN 0950-1991.
- ^ a b Biggers, J. D. (1998). "Reflections on the culture of the preimplantation embryo". The International Journal of Developmental Biology. 42 (7): 879–884. ISSN 0214-6282. PMID 9853817.
- ^ Ho, Yugong; Wigglesworth, Karen; Eppig, John J.; Schultz, Richard M. (1995-06-01). "Preimplantation development of mouse embryos in KSOM: Augmentation by amino acids and analysis of gene expression". Molecular Reproduction and Development. 41 (2): 232–238. doi:10.1002/mrd.1080410214. ISSN 1040-452X. PMID 7654376. S2CID 24036963.