But horseshoe crab amebocytes are exceptionally sensitive to bacterial endotoxins.

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.

内毒素来自某些细菌（包括大肠杆菌）细胞壁分子。

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

他们将 LAL 添加到药物样品中， 如果形成凝胶，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 LAL 取物来检测内毒素，这种取物从捕获血液中取。

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.

我们确实有称革兰氏染色检测细菌测试，它们无法识别即使不存在细菌也可能存在内毒素。