With the precious new concentrate, however, our patient’s hemostasis during dental extractions was perfectly normal. Cutter could not produce much of this marvellous material because the yield of concentrated FVIII from plasma was low. Enter Dr. Judith Graham Pool. She had earned her Ph.D. in physiology from the University of Chicago in 1946 and had joined the faculty of Stanford SCH772984 University in 1953, investigating coagulation with particular attention to FVIII. With Jean Robinson, she had developed the ‘two-stage’ assay for FVIII in 1959.

In the early 1960s she used that method to assay FVIII in plasma fractions prepared by Cutter’s Drs. Albert Pappenhagen and Edward Hershgold. Their starting material

was pooled plasma, frozen in large containers, which they thawed cautiously. They knew that the potency of FVIII in plasma dwindled at room temperature, so they were careful not to thaw the plasma completely. buy Alvelestat But Dr. Pool found very little FVIII in their thawed supernatant. She then tested the small amount of unthawed, fibrous-looking paste at the bottom of the containers, and, in 1964, found the FVIII [5]. The genius of Dr. Pool was her leap from that laboratory observation to the practical idea of using the last-to-thaw property of FVIII to separate ‘cryoprecipitate’ from whole plasma in an ordinary blood bank, re-freezing the small volume in its own sterile plastic bag and storing bags in a freezer so that eventually several could be given to a patient at one time [4]. Meanwhile, the thawed plasma could be used for extraction of other plasma proteins. The method was so simple, and

cost so little for the additional materials, that it was rapidly copied by blood banks around the world. Cryoprecipitate became widely available not only for patients with haemophilia A or von Willebrand disease but also for patients deficient in fibrinogen or factor XIII. It was a great, miraculous gift to the world. Many tens of thousands of patients have benefitted. Meanwhile, more highly concentrated commercial, lyophilized FVIII preparations were developed, using various technologies (often including Bcl-w cryoprecipitation). The first was licensed in the USA at the end of the 1960s and then cost ten cents (U.S.$0.10) per FVIII unit in Los Angeles. We quickly adopted its use and, by 1970, started to introduce our haemophilia patients to self-infusion at home. Our local blood bank had switched from the use of glass bottles for blood collection to plastic bags only in the late 1960s, delaying the development of cryoprecipitate. Furthermore, instead of charging only the incremental costs of the additional processing required to extract cryoprecipitate from plasma, they divided the total cost of blood processing among all components.