They also chose a relatively cheap technology , called mass spectrometry , to analyze dna .
他们还采用了一种相对便宜的质谱技术来分析dna。
They used a technique called secondary ion mass spectrometry ( sims ) , which allowed them to analyze the grains for a compound known as hydroxyl , which can be incorporated into apatite 's chemical structure if the mineral crystallizes from magma that contains water .
They also separated out the dna from the bacteria and analyzed its composition using a technique called high-resolution secondary ion mass spectrometry ; the isolated dna contained arsenic .
The technique , called secondary ion mass spectrometry , was developed to detect trace amounts of volatile gases such as chlorine and fluorine in earth soil samples .
