Usually, age is determined by physical characteristics, such as teeth or bones. Great if you have a body. Researchers have tried unsuccessfully to use blood. But in this study, the scientists used immune cells called T-cells. T-cells recognize invaders through receptors that match molecules on bacteria, viruses, even tumors. The cellular activity that produces these receptors also produces a type of circular DNA molecule as a by-product.
PTELook at the text below. In 35 seconds, you must read this text aloud as naturally and clearly as possible. You have 35 seconds to read aloud.
Recorded Answer
Current status:
Beginning in 35 seconds.