What’s new (and old) at the Dittrick? Portable lab kits and testing devices!

Want to see these objects in person? This exhibit is currently on display on the second floor of the Allen Memorial Medical Library. Click here for the library’s hours of operation.

Did you know that portable medical testing kits and devices have a long history? The early 20th century artifacts in this exhibit don’t connect to an app on your smartphone, but they were effective tools for clinicians and patients who needed to measure health indicators such as blood glucose but didn’t have access to a full clinical laboratory.

Monitoring glucose levels is critical for the management of diabetes, a condition where the body cannot maintain safe blood concentrations of glucose without the aid of medications (e.g. insulin) and/or a controlled diet. The Benedict test, developed in 1909 is a multi-step process requiring the careful measurement, mixing of solutions, and application of heat to estimate the amount of glucose in a urine sample. Performing and interpreting the Benedict test was especially important after insulin became available in 1922 as dosage was based on glucose levels. Patients and their caregivers became amateur bench scientists, experts at correctly executing and interpreting chemical tests in their own bathrooms and kitchens. Reagent testing strips, on the marketing beginning in the 1970s, simplified glucose testing outside of the clinic, but they present their own technical shortcomings. The accuracy, portability, and affordability of digital blood glucose monitors continues to be a challenge today.

With automated procedures the norm, it’s easy to forget that clinical laboratory results are based on the interpretations of a human (or a computer programmed by a human). The devices shown here measure hemoglobin, the substance that transports oxygen within red blood cells. These hemoglobinometers require the examiner to match the color of a prepared blood sample to a standard. How accurate do you think these tests were? Does one type seem more trustworthy to you than the others? Why? We understand automated laboratory machines as more reliable and accurate than a laboratory technician, and they often are. However, some tests are best performed by a human. For example, a manual differential blood cell count completed by a lab tech is more reliable for diagnosing early-stage bacterial infections than an automated count. Does that surprise you? As part of this test, the technician identifies each white blood cell in a sample under a microscope based on their expertise and tallies each category using a counter. Why might this manual approach work better than an automated count?