But horseshoe crab amebocytes are exceptionally sensitive to bacterial endotoxins.

但是鲎变形细胞对细菌内毒素异常敏感。

Endotoxins are molecules from the cell walls of certain bacteria, including E. coli.

内毒素是来自某些细菌（包杆菌）细胞壁的分子。

They add LAL to a medicine sample, and if gels form, bacterial endotoxins are present.

他们将 LAL 添加到药物样品， 形成凝胶，则表明存在细菌内毒素。

So scientists use an extract called LAL produced from harvested horseshoe crab blood to test for endotoxins.

因此， 科学家们使用一种名为 LAL 的提取物来检测内毒素，这种提取物是从捕获的鲎血液提取的。

We do have tests called Gram stains that detect bacteria, but they can't recognize endotoxins which can be there even when bacteria aren't present.

我们确实有称为革兰氏染色的检测细菌的测试，但它们无法识别即使不存在细菌也可能存在的内毒素。