Emily was sick. The 3-month- old baby girl was feverish and had trouble breathing.

When her mother took Emily to the pediatrician’s office, the physician was faced with a diagnostic dilemma. If Emily was suffering from a bacterial infection, then antibiotic treatment might be very helpful in aiding her recovery. If, however, the congestion was caused by a virus, then antibiotic medication would not be helpful. In an adult person, serious bacterial infections may cause an elevated total white blood cell count while viral infections may depress the total white blood cell count below normal levels. But in an infant, that test is not as dependable a criterion.

In an adult, one type of white blood cell, named a neutrophil, usually is elevated in numbers with a bacterial infection.

Also in the adult, a viral infection may elevate a different type of white blood cell called a lymphocyte. But in small children the lymphocyte may be the normal predominant white blood cell.

So, how could the doctor know?

An Asian researcher came up with an answer to this dilemma and published his research results in the British medical journal Lancet. But his laboratory procedures could not be reproduced in the laboratories of Ohio State University where I was employed. While the published test results were encouraging, the methods for obtaining those results remained a dilemma.

Against this background, my graduate professor and advisor suggested I make this challenge the subject of my research and eventual written thesis.

He arranged for me to have the exclusive use of a small laboratory and the university supplied me with a stipend to cover the living expenses for myself and my family. Thus, I could devote my full time to research and writing for about a year.

The test is called the NBT test, short for nitro-blue-tetrazolium.

Neutrophil white blood cells, which can surround and engulf bacteria, will also surround and engulf particles of NBT.

When the body detects a major bacterial infection the neutrophils become more active and greater numbers of neutrophils engulf NBT particles.

A stained blood smear shows the percentage of neutrophils with engulfed black deposits.

In viral infections, the number of neutrophils showing the black deposits remain in the normal range of an uninfected person.

My research showed that heparin, a body chemical which prevents blood clotting, has a role in the test, of regulating also the engulfing activity of the neutrophils.

This was a key finding which helped us to define a test method useful in our own university laboratories.

The Asian researcher had published some information which our own research could not support. We attained a useful testing methodology.

But generally, the NBT test is not widely used today.

Emily was given a precautionary antibiotic; put in a high-water-vapor tent and recovered uneventfully.