Storage of marine fish erythrocytes in liquid nitrogen

Abstract

The preservation of erythrocytes from cod (Gadus morhua), saithe (Pollachius virens) and mackerel (Scomber scombrus) at -196" C was studied using dimethyl sulphoxide (DMSO) as a cryoprotectant. Erythrocyte recoveries of greater than 90% were obtained from all species and cod erythrocytes were stored for eighteen months with insignificant lysis. Larger quantities of blood were stored by removal of plasma from citrated blood prior to the addition of DMSO solution, and by storage of pelleted frozen blood in aluminium canisters in liquid nitrogen. Maximum recoveries of washed intact erythrocytes required thawing of pellets in 125% DMSO solution and washing with buffer containing decreasing concentrations of DMSO. Washed erythrocytes kept at 4" for at least two days showed little haemolysis, were morphologically similar to fresh erythrocytes and equally susceptible to the 6-haemolysin of Staphylococcus aureus.

Inhibition of staphylococcal delta-haemolysin by human serum lipoproteins

“…Purification and assay of the 8-haemolysin of Staphylococcus aureus strain NCTC 10345 have been described previously [6]. One haemolytic unit (HUso) was the amount of 5-haemolysin which produced 50% haemolysis after 30 min at 20°C.…”

Evidence for two haemolytic activities from Aeromonas salmonicida

“…Tryptone soya broth 4 16 Furunculosis broth 4 32 Peptone broth 3 48 Peptone + yeast extract broth tions may be achieved by the long-term storage of cells [13]. Fig.…”