请教一个英语句子分析,请高手帮忙一下,谢谢

Israeli(以色列) scientists have built a DNA compute so tiny that a trillion of them could fit in a test tube and perform a billion operations per second with 99.8 percent accuracy.

这句话看不懂.特别是"a trillion of them could fit in a test tube ",请高手指教,先谢谢了...