They collect blood samples for analysis at a national laboratory.

他们收集血样以在一个国家实验室做化验分析。

《柯林斯英汉双解大词典》

Bethune organized a service to collect blood from donors and deliver it to the battlefront, thereby saving countless lives.

白求恩建立了采集献血者血液的服务，并将血液运送到前线，从而拯救了无数的生命。

youdao

The first time I faced a real HIV infection, and to collect blood for him personally, and my heart is somewhat nervous, because AIDS is still a reference for all fear.

我第一次真正的面对一个艾滋病病毒感染者，并要亲自为他采集静脉血，心里多少有些紧张，因为一提到艾滋病还是让所有人恐惧的。

youdao

What if I collect that blood from patients that are already infected with Hepatitis B, purify the Hepatitis B protein, and inject that back into people?

如果我采集那些乙肝患者的血液,抽提出乙肝病毒的蛋白质,并且将其回注入人体内,将会如何呢

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