Potassium Simplex Optimized Medium (KSOM) is a specialized medium primarily used for in vitro culture of mouse preimplantation embryos in research. [1] [2]
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]
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]
Potassium Simplex Optimized Medium (KSOM) is a specialized medium primarily used for in vitro culture of mouse preimplantation embryos in research. [1] [2]
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]
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]