Haemoglobin (Erythrogen)-enhanced post-thaw growth of cryopreserved cells

Supplementation of semi-solid R2 culture medium with a commercial bovine haemoglobin (Hb) solution (Erythrogen) at 1:50-1:500 (v:v), had beneficial effects on the growth, following cryopreservation, of cells of the Indica rice, Oryza sativa cv. Pusa Basmati 1. The mean absorbance, as assessed by triphenyl tetrazolium chloride reduction, of rice cells at 8 d post-thawing, was increased by up to 60% (P < 0.05), compared to cells recovered in the absence of Hb. Erythrogen (1:50-1:500 v:v) promoted an increase in biomass, of up to 25% over control (P < 0.05), at 24 d post-thawing. Cell suspensions, re-established by transfer to liquid medium of cells initially thawed and cultured with Erythrogen for 24 d, exhibited increased (up to 2-fold) growth rates over a subsequent 20-d period, compared to cells recovered without Hb.