These are nutrient-rich liquids (media) supplemented with animal serum (often Fetal Bovine Serum) to provide growth factors for human or animal cells.
It allows producers to create high-quality sounds from scratch using visual wavetables. Serum Media Wiki
A limited liability company registered in Jēkabpils, primarily involved in accounting and tax consultancy services. Firmas.lv - Serum Media and electronic music)
While not a "media" company, is a widely famous wavetable synthesizer by Xfer Records . Because it is a staple of modern "media" production (film scores, video games, and electronic music), many wikis exist for it: Serum Media Wiki
This is a major topic on Wikipedia (Chemically Defined Medium) and OpenWetWare , where researchers document protocols for maintaining cell viability.
There are several independent companies operating under this name:
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