Injection Medium
6% Ficoll PM400 (e.g., Sigma-Aldrich GE17-0300-10)
0.1× MBS (pH 7.5) (diluted from Modified Barth's Saline for Xenopus (MBS))
Filter-sterilize and freeze at −20°C for long-term storage or store for up to a week at 4°C. For use, warm up to 22°C or room temperature. The pH may become acidic after use for a few days or after long-term storage. We add a small amount of phenol red (e.g., 4–5 µL per 100 mL) so that we can monitor pH roughly by visually checking color change. Readjust pH as needed before use.
