They used to have procedures that said if pump number one breaks you do this particular step, if pump number two breaks you do this particular step.

它们曾经有些步骤是说，如果泵1断裂了，你们就要做这个特别的步骤，如果泵2断裂了，你们要做这个特别的步骤。

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An amplified immunoassay with improved sensitivity has been proposed based on two-step amplification procedures of enzyme-catalyzed precipitation and biotin-streptavidin binding system (in Chapter 3).

在用于实际试样的回收率测定中，结果良好。(2)提出了一种基于酶催化沉积底物和生物素-亲和素两步放大的超灵敏免疫检测方法(第3章)。

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