Storage of blood for methemoglobin determination: comparison of storage with a cryoprotectant at -30 degrees C and without any additions at -80 degrees C or -196 degrees C.
Changes in methemoglobin (Met-Hb) concentrations during storage of whole blood or mixtures of blood and a cryoprotectant at refrigerated or various freezing temperatures were examined using blood samples from nitrite-administered rats and from autopsy cadavers. When whole blood was stored at 3 degrees C, Met-Hb reduction was observed in blood samples from nitrite-administered rats and in the blood from a victim poisoned by a weed killer containing some oxidant. When samples were stored at -30 degrees C, Met-Hb formation by autoxidation was inevitably observed in blood samples stored as whole blood, whereas addition of a cryoprotectant to whole blood could prevent Met-Hb formation in all the blood samples. When whole blood was stored at -80 degrees C or -196 degrees C, Met-Hb concentrations were practically stable until at least 30 days regardless of the initial values except in the control rat blood samples stored at -80 degrees C which showed slight formation of Met-Hb. From the results obtained, both the storage with a cryoprotectant at -30 degrees C and that without any additions at -80 degrees C or -196 degrees C proved to be suitable for long-term storage of blood samples from autopsy cadavers for Met-Hb determination.
Sato
K
K
Department of Legal Medicine, Nagoya University School of Medicine, Japan.
Tamaki
K
K
Tsutsumi
H
H
Okajima
H
H
Katsumata
Y
Y
D000818:Animals; D001793:Blood Preservation; D015925:Cryopreservation; D003451:Cryoprotective Agents; D042966:Cytochrome-B(5) Reductase / Q000378:metabolism; D004355:Drug Stability; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008706:Methemoglobin / Q000032:analysis*; D009573:Nitrites / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains
D003451:Cryoprotective Agents; D009573:Nitrites; D008706:Methemoglobin; D042966:Cytochrome-B(5) Reductase