A lyophilized hemoglobin control prepared from stroma-free hemolysates

We prepared a stable lyophilized hemoglobin control from human erythrocytes by removing stroma with calcium and Ficoll. Addition of polyhydroxy compounds enhanced reconstitution and stability. The lyophilized product was stable during one year of use in a service laboratory. Accelerated aging studies demonstrated the potential of up to two years of stability, with methemoglobin increasing at a projected rate of approximately 6% per year. Reconstituted, the control gave reproducible values for at least five days when refrigerated.