Linus Pauling: He [Harvey Itano] tried a number of tests. The two hemoglobins seemed to be the same - oxygen equilibrium curve and spectrum.
But here, unless you get a difference, it's just a surmise that they are the same. When you don't observe a difference there
may be a difference, as Professor Dickinson was pointing out to me in 1922, there may be a difference. So, our problem was
that you couldn't buy a Tiselius apparatus. So we started building one, and it was quite a job. We had to have a big room
because it was about 30 feet long tube, 30 feet long. It took a couple of years to get this apparatus built.
Here we have the results. [slide] Normal hemoglobin at pH 7 moved toward the anode sickle cell anemia hemoglobin and the hemoglobin
from a sickle cell anemia patient moved towards the cathode. And the mixture of the two was split. We mixed these two bloods,
here, blood from either the father or the mother of the sickle cell patient came out like this. Two kinds of hemoglobin. They
were heterozygotes. This hadn't been recognized, that this was a genetic disease of that sort where the manifestations of
the disease showed up in the homozygote.
So that led to a lot of progress. Dr. Harvey Itano and his other people in the laboratory found hemoglobin C and hemoglobin
D and hemoglobin E. Schroeder and I reported that there are two kinds of polypeptides chains in the hemoglobin molecules,
two alpha chains and two beta chains. Other people began finding abnormal hemoglobins. The field of the hemoglobinopathies
was built up. I think there are more than two-hundred kinds of human hemoglobin that have been reported so far.