The Coulter Principle
Robert C. Leif, Ph.D.
rleif at rleif.com
Mon May 25 11:12:00 EST 1998
From: Bob Leif, Ph.D.
After reading the thread on the history of the Coulter Principle, I
recognized that most of the information was totally inaccurate from what
Wallace had told me. I checked with Robert I. Klein, who worked with
Wallace in the basement. Robert was Coulter's first and best Engineering
Manager. Besides being responsible for bring out many of Coulters products,
Robert made many fundamental contributions to analytical cytology including
coincidence correction and building the first microprocessor based
commercial hematology instrument.
Written by Robert I Klein
To the best of my knowledge, the medical and industrial applications
developed in parallel during the basement days. You are correct in stating
that erythrocyte counting was first. However, counting red cells was not
medically useful in the eyes of the clinician during this initial period.
The medical market took off and over 3,000 Model A Coulter Counters were
sold only after a method was developed to destroy the red cells and count
the remaining white cells. As you know, white cell counts were commonly
ordered during this period and the ability for better statistics was an
During the basement days, engineering needed more room and we moved to a
furnished apartment over a laundry on Broadway a few blocks from the
basement. We had two chief engineers- Walt Hoag and Abe Siegelman
responsible for medical & industrial applications respectively. In
addition, the Coultamp Company was formed to develop another of Wallace's
patents that involved using electrocardiograph amplifier concepts to make
the world's best stereo amplifier. Unfortunately, this was done with vacuum
tubes and the existence of cheap power transistors killed it.
During this time, and for the first six years in Hialeah, more engineering
effort was applied to industrial applications than medical. This was
because of the large number of different applications each with the
potential of limited markets. The medical products, on the other hand, were
fewer but had a very large potential market as history has proven. I do not
know- and certainly would not presume- to guess what was in Wallace's head
but, based upon the emphasis that he urged, the medical and industrial
efforts were relatively equal.
Specific to the comments on aviation fuel: Efforts to determine particulate
contamination began much later- only after the discovery of bacteria that
could live in kerosene. Many other applications were developed long before.
Here is a sample of some that I can remember that are earlier: toner
grinding, talc, fritz, hydraulic fluid contaminants, the thickness of wool,
particulate contamination of injectables and colored TV CRT phosphors, to
name a few.
I have no knowledge of the sizing of coffee granules, but there is no reason
why not as even fish eggs were measured. As an aside, the Model A had a
sister called the Model K with lower noise components and wider dynamic
range specifically for the industrial market. The sample stand was
significantly upgraded to accommodate better shielding and corrosive
If you need any more information, let me know.
More information about the Cytometry