April 1961: New Device for Blood Cell Counts #throwbackthursdays

Vera Hanson, supervisor of the routine hematology laboratory, observes as Phyllis Johnson carries out blood counts on the Coulter counter. The sample is taken up by suction in the aperture tube assembly at right and is carried through the counter.
Vera Hanson, supervisor of the routine hematology laboratory, observed as Phyllis Johnson carries out blood counts on the Coulter counter. The sample is taken up by suction in the aperture tube assembly at right and is carried through the counter.

In April 1961, Mayo Clinic implemented Coulter electronic erythrocyte (red blood cell) counters in the Section of Clinical Pathology. The devices expedited the time required for a blood test, including dilution of the sample, to just a little more than a minute.

Esther McFarland, assistant supervisor, uses the automatic blood diluting pipet which was perfected in the Section of Engineering.
Esther McFarland, assistant supervisor, used the automatic blood diluting pipet which was perfected in the Section of Engineering.

As the cells in a diluted blood sample are drawn through an aperture 100 millimicrons in diameter, they lower the electrical conductivity of the electrolyte (sodium chloride) in which they are suspended, causing an impulse to be amplified and record on an electric counter. The device computes the sum of these impulses, applies a “built-in” correction factor, and the number of cells per cubic millimeter of blood is automatically recorded by an electric typewriter on a laboratory report form.

The change-over from the visual to the electronic method of counting red cells was not as simple as purchasing a new device and plugging it into an electrical outlet. Intensive studies of every phase of the new method were carried out over a period of more than year and the successful adaptation of the electronic counter to routine laboratory use came about through the cooperative efforts of many Mayo Clinic personnel.

According to Dr. Don R. Mathieson, head of Clinical Pathology laboratories at the time, “We have in this device an eye which sees and a brain which counts. With it greater accuracy and greater ease in performance have been achieved.”

Lydia Roberts supervised the meticulous, dust-free preparation of 156,000 vials used by the laboratory in a year.
Lydia Roberts supervised the meticulous, dust-free preparation of 156,000 vials used by the laboratory in a year.

The classical method for determining the number of red cells in the blood was for a technician literally to count the number of cells visualized through a microscope. An error has high as eight percent was inherent in this method. Using the Coulter counter, the error was reduced to about two percent.

The accuracy of the automatic method is largely the result of the large number of cells counted—the automatic counter counted 50,000 red cells in 15 seconds; the human eye could count only 500 cells in about four minutes.

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Kelley Schreiber

Kelley Schreiber is a Marketing Channel Manager at Mayo Medical Laboratories. She is the principle editor and writer of Insights and leads social media and direct marketing strategy. Kelley has worked at Mayo Clinic since 2013. Outside of work, you can find Kelley running, traveling, playing with her new kitten, and exploring new foods.