Medicine: Vital Fractions

Blood is full of a number of things. There are the red cells, which contain oxygen-carrying hemoglobin and are used in transfusions for anemia.There are white cells, which rush to defend the system against bacterial invasion. There are the little-understood platelets, which help in clotting. Besides these solids, there is the amber fluid (plasma), which contains a score or more different components, some already being used in medicine, others still in the research stage. To separate these various fractions, preserve them and make them available for medical use is a vastly complex process.

Last week a shiny, 32-foot trailer truck lumbered up to the General Electric Co.’s laboratories at Schenectady, N.Y. A procession of 25 blood donors trooped in at one end. Within a few hours, out came twelve different components of human blood, all neatly separated and refrigerator-packed to hold their freshness and life-saving powers as long as possible. The world’s first “blood factory on wheels,” developed by a Harvard University research group, was being demonstrated to the National Academy of Sciences.

Settling Red. Chief demonstrator was Harvard’s Professor (of Biochemistry) Edwin Joseph Cohn, whose research made the mobile laboratory possible. Because blood begins to deteriorate as soon as it leaves the veins, the needle used by Dr. Cohn’s team has a special inside coating to keep the white cells from sticking to its sides and being destroyed. From the needle the blood flows through a plastic tube lined with a resinous compound to remove the calcium and keep it from clotting.

After that, Dr. Cohn showed how the blood goes through a maze of tubes and a series of whirling cylinders. In a plastic bag lined with a gummy substance, the red cells settle to the bottom. Thus separated, said Dr. Cohn, they can be kept for at least a year (whereas by older methods they were good for less than a month).

Whirling White. The rest of the blood passes to the centrifuges. Whirled around first at 120 Gs (a speed giving the effect of gravity multiplied 120 times), the white cells are separated. Then spun at 400 Gs, the fluid yields its platelets (small, light-grey cells). That takes care of the solids.

The fluid part of the blood goes through more centrifuges and chilling processes. Out come a serum globulin (used to prevent or control measles), serum albumin (for treatment of shock), fibrinogen, thrombin and prothrombin — and more components of blood for which medical science has not yet found uses.

The Mobile Blood Processing Laboratory can handle 200 pints of donor’s blood a day. Soon, Dr. Cohn hopes, it will be as familiar as the Red Cross Bloodmobile —and will be parked right behind it as the nation stores up blood fractions.