A taste test leads to your own DNA

Students at THI have been investigating why people perceive bitter substances differently in the Digital Medicine laboratory. To do this, they compared their personal taste perceptions with the results of an analysis of their own DNA.

Thumbs up? It depends on your genes. In a molecular biology lab course at THI, students investigate why some people perceive the bitter compound PTC very intensely – while others barely taste it at all (Photo: THI).

“Yuck, that’s bitter!” Whilst some immediately pull a face, others look up, puzzled. “I can’t taste a thing.” The trigger for these differing reactions is a narrow strip of paper – and a question that students at THI are investigating in the wet lab: why do people perceive the same taste so differently?

A molecular biology practical experiment focused on precisely this phenomenon. The participants analysed a section of the TAS2R38 gene, which influences the perception of certain bitter substances. To do this, they first extracted DNA from their own buccal mucosa cells. They then used various molecular biology techniques to identify genetic variants and evaluate them.

Only then did the taste test take place. Using special test strips, the students checked their reaction to the bitter substance phenylthiocarbamide, or PTC for short. Whilst some perceive it as intensely bitter, others hardly notice any difference. A comparison with the laboratory results showed that the cause may indeed lie in the genetic makeup.

“When students compare their genetic results with their own taste perceptions, it often leads to a real ‘aha’ moment,” says Professor Matthias Eckert. “The experiment demonstrates how even the smallest differences in genetic makeup can affect everyday perceptions.”

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