Cortland's salt solution

For a 100 mL volume, dissolve the following in distilled water:
725 mg NaCl (124.1 mM)
38 mg KCl (5.1 mM)
41 mg Na2HPO4 (2.9 mM)
24 mg MgSO4∙7H2O (1.9 mM)
16 mg CaCl2∙2H2O (1.4 mM)
100 mg NaHCO3 (11.9 mM)
4 g Polyvinylpyrrolidone (PVP) (4%)
1,000 USP units Heparin
Filter, sterilize and store at 4°C.

Perry, S.F., Davie, P.S., Daxboeck, C., Ellis, A.G., & Smith, D.G. (1984). Perfusion methods for the study of gill physiology. In W.S. Hoar & D.J. Randall (Eds.), Gills: Part B. Ion and water transfer (series title: Fish physiology, vol. 10). Orlando: Academic Press.