Alkaline electrophoresis
In general on alkaline electrophoresis in order of increasing mobility are hemoglobins A2, E=O=C, G=D=S=Lepore, F, A, K, J, Barts, N, I, and H.In general a sickling test is performed on abnormal hemoglobins migrating in the S location to see if the hemoglobin precipitates in solution of sodium bisulfite. Acid electrophoresis
In general on acid electrophoresis in order of increasing mobility are hemoglobins F, A=D=G=E=O=Lepore, S, and C.This is how abnormal hemoglobin variants are isolated and identified using these two methods. For example, a Hgb G-Philadelphia would migrate with S on alkaline electrophoresis and would migrate with A on acid electrophoresis, respectively

Evolution
Some hemoglobinopathies (and also related diseases like glucose-6-phosphate dehydrogenase deficiency) seem to have given an evolutionary benefit, especially to heterozygotes, in areas where malaria is endemic. Malaria parasites live inside red blood cells, but subtly disturb normal cellular function. In patients predisposed for rapid clearance of red blood cells, this may lead to early destruction of cells infected with the parasite and increased chance of survival for the carrier of the trait.Hemoglobin functions:

Transport of oxygen from the lungs to the tissues: This is due to the peculiar cooperation of the globin chains that allows the molecule to take in more oxygen where there is increased oxygen and to release oxygen in low concentration of oxygen. Transport of carbon dioxide from the tissues to the lungs: The end product of tissue metabolism is acidic which increases hydrogen ions in solution. The hydrogen ions combine with bicarbonates to produce water and carbon dioxide.
The organic stream is recycled through the solvent extraction process while the aqueous streams cycle through leaching and electrowinning processes respectively. Ion exchange
Chelating agents, natural zeolite, activated carbon, resins, and liquid organics impregnated with chelating agents are all used to exchange cations or anions with the solution. Selectivity and recovery are a function of the reagents used and the contaminants present. Metal recovery
Metal recovery is the final step in a hydrometallurgical process. Metals suitable for sale as raw materials are often directly produced in the metal recovery step. Sometimes, however, further refining is required if ultra-high purity metals are to be produced. The primary types of metal recovery processes are electrolysis, gaseous reduction, and precipitation. For example, a major target of hydrometallurgy is copper, which is conveniently obtained by electrolysis. Cu2+ ions reduce at mild potentials, leaving behind other contaminating metals such as Fe2+ and Zn2+. Electrolysis
Electrowinning and electrorefining respectively involve the recovery and purification of metals using electrodeposition of metals at the cathode, and either metal dissolution or a competing oxidation reaction at the anode. Precipitation
Precipitation in hydrometallurgy involves the chemical precipitation of either metals and their compounds or of the contaminants from aqueous solutions. Precipitation will proceed when, through reagent addition, evaporation, pH change or temperature manipulation, any given species exceeds its limit of solubility. References
External links
Hydrometallurgy, BioMineWiki