Bethany students test their own genetics

GOSHEN — Bethany Christian’s Chemistry II students studying genetics recently tested themselves for the presence of the PTC gene, which is a mutation found on chromosome 7.

This mutation gives about 70 percent of humans the ability to taste the bitter compound phenylthiocarbamide, communications coordinator Kevin Miller said. Students collected and isolated DNA samples from their cheek cells, and then used the polymerase chain-reaction process that involves heating and cooling the DNA with various primers and enzymes — in this case, for 35 cycles — followed by several additional steps.

Students confirmed their results by tasting a small strip of paper that had been soaked in PTC, Miller reported. The small sample of seven students followed closely that of the general human population, with two students having no bitter taste, two having strong bitter taste and three having slight bitter taste.

This was the first time Bethany students have been able to conduct this experiment, he said, thanks to Harold Cross, a 1956 Bethany alum and medical doctor and professor who has spent much of his professional career studying genetic diseases among the Amish. Cross donated funds for Bethany to purchase a PCR thermocycler, which greatly simplifies the normally time-consuming and arduous process needed for this experiment, Miller said.