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验孕棒的检测原理是什么?

How do pregnancy tests work? - Tien Nguyen

The earliest known pregnancy test
已知最早的验孕方法
dates back to 1350 BC in Ancient Egypt
可追溯至公元前1350年的古埃及
According to the Egyptians,
据古埃及人记载
all you have to do is urinate on wheat and barley seeds, and wait.
你只需在小麦和大麦种子上排尿 然后等待
If either sprouts, congratulations, you’re pregnant!
如果其中一个发芽了 恭喜你 你怀孕了!
And if wheat sprouts faster, it’s a girl,
如果小麦种子发芽更快就是女孩
but if barley, it’s a boy
如果大麦种子发芽更快就是男孩
In 1963, a small study reproduced this test
1963年 一项小型研究再现了这一测试
and found that it predicted pregnancy with a respectable 70% accuracy,
尽管它并不能准确地判断孩子的性别
though it couldn’t reliably tell the sex of the baby.
但其验孕准确率高达70%
Scientists hypothesized that the test worked
科学家推测这项测试之所以可行
because pregnant women’s urine contains more estrogen,
是因为怀孕的女性尿液中含有大量雌性激素
which can promote seed growth.
这些激素可以促进种子生长
Now it’s easy to take this ancient method for granted
现在已经不用这个古老的方法了
because modern pregnancy tests
因为现代验孕方法
give highly accurate results within minutes.
可在几分钟内给出非常准确的结果
So how do they work?
所以现代检测的原理是什么呢?
Over-the-counter pregnancy tests are all designed to detect one thing:
非处方验孕棒的设计都是为了检测一项指标:
a hormone called HCG.
一种叫HCG的激素
HCG is produced in the earliest stages of pregnancy
HCG在怀孕的早期产生
and starts a game of telephone
然后开始一场电话游戏
that tells the body not to shed the inner lining of the uterus that month.
告诉身体这个月不要让子宫内膜剥落
As the pregnancy progresses,
在怀孕过程中
HCG supports the formation of the placenta,
HCG可以帮助形成胎盘
which transfers nutrients from mother to fetus.
胎盘可以将妈妈的营养传送给胎儿
The test starts when urine is applied to the exposed end of the strip.
验孕棒检测要先把尿液加到验孕棒露出的末端
As the fluid travels up the absorbent fibers,
当液体流过有吸收能力的纤维时
it will cross three separate zones,
会经过三个独立的区域
each with an important task.
每个区域都有重要的功能
When the wave hits the first zone, the reaction zone,
当液体流到第一个区域 反应区
Y-shaped proteins called antibodies will grab onto any HCG.
被称为抗体的Y形蛋白质会和任意的HCG结合
Attached to these antibodies is a handy enzyme
这些抗体上附着了一种方便使用的酶
with the ability to turn on dye molecules,
酶可以激活染料分子
which will be crucial later down the road.
这在下游反应中非常重要
Then the urine picks up all the AB1 enzymes
然后尿液会把所有的AB1酶
and carries them to the test zone, which is where the results show up.
带到测试区 这里会显示结果
Secured to this zone are more Y-shaped antibodies
为了使结果更可靠 这个区域有更多Y型抗体
that will also stick to HCG on one of its five binding sites.
它们的五个结合部位都可以和HCG结合
Scientists call this type of test a sandwich assay.
科学家把这种测试称为夹心测试法
If HCG is present,
如果有HCG出现
it gets sandwiched between the AB1 enzyme and AB2
它们会被夹在AB1酶与AB2酶之间
and sticks to the test zone,
并黏附在测试区
allowing the attached dye-activating enzyme to do its job
附带的染色激活酶就可以发挥作用
and create a visible pattern.
产生一个可以看到的图案
If there’s no HCG,
如果没有HCG
the wave of urine and enzymes just passes on by
尿液和酶就会继续流下去
Finally, there’s one last stop to make, the control zone.
最后 还有最后一站 控制区
As in any good experiment,
在任何符合标准的测试中
this step confirms that the test is working properly.
这一步会默认前面的测试没有问题
Whether the AB1 enzymes never saw HCG,
无论是AB1酶从未发现HCG
or they’re extras because Zone 1 is overstocked with them,
还是在反应区里有太多HCG
all the unbound AB1 enzymes picked up in Zone 1
所有在反应区里带来的AB1酶
should end up here and activate more dye.
都会在这里结束并激活更多染色反应
So if no pattern appears, that indicates that the test was faulty.
因此如果没有出现图案 表明测试失败
These tests are pretty reliable, but they’re not failproof.
测试结果非常可信 但也会失败
For instance, false negatives can occur
例如 如果HCG量太少无法检测出来
if concentrations of HCG aren’t high enough for detection.
就会产生假阴性反应
After implantation, HCG levels double every two to three days,
受孕后 HCG的水平每两到三天就会翻倍
so it may just be too early to tell.
所以过早可能无法检测到
And beverages can dilute the urine sample,
饮料也会稀释尿液样本
which is why doctors recommend taking the test first thing in the morning.
这就是为什么医生建议一起床就做这个测试
On the other hand, false positives can come from other sources of HCG,
另一方面假阴性反应可能来自于其他HCG
like IVF injections, ectopic pregnancies,
像试管婴儿注射剂 异位妊娠
or certain cancers such as uterine cancer or testicular cancer,
或者某种癌症 如子宫癌或睾丸癌
making it possible for one of these tests to tell a man he’s pregnant.
其中一种情况也可能会显示某位男士怀孕
The best way for a woman to find out for sure
女士们想要确认怀孕的最好办法
is at the doctor’s office
就是去看医生
The doctors are also looking for HCG,
医生也会检测HCG
but with tests that are more sensitive and quantitative,
但医生的测试会更加灵敏 更加量化
which means they can determine the exact level of HCG in your blood.
他们可以精确地检测你血液中HCG的水平
A few minutes can feel like forever
在你等待验孕结果时
when you’re waiting on the results of a pregnancy test.
短短几分钟似是永恒
But in that brief time,
但在那短短的时间里
you’re witnessing the power of the scientific method
你见证了科技的力量
That one little stick lets you ask a question,
那小小的棒子让你产生了疑问
perform a controlled experiment,
完成了一个对比实验
and then analyze the results to check your original hypothesis.
然后分析结果并验证最初的假设
And the best part is you won’t even have to wait until the next harvest.
最大的好处就是你不用等到下一次收割

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视频概述

古埃及是怎么进行怀孕检测的?现代科技又是如何进行怀孕检测的?验孕棒的检测原理是什么呢?快来一起看一看吧

听录译者

收集自网络

翻译译者

Polaris

审核员

审核员NEHC

视频来源

https://www.youtube.com/watch?v=aOfWTscU8YM

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