Agar was first introduced into the laboratory in 1881. Since then, microbiologists have depended on agar to create strong jellies. When microorganisms are streaked or plated onto this jellied surface and incubated, individual cells multiply into distinct colonies that scientists can easily observe, select, and propagate for further experiments. Many of the most important findings in biological research of the last 150 years or so — including the discovery of the CRISPR/Cas9 gene-editing tool — have been enabled by agar.4 Agarose, a derivative of agar, is also essential in molecular biology techniques like gel electrophoresis, where its porous gel matrix separates DNA fragments by size, enabling researchers to analyze and isolate specific genetic sequences.
Ultimately, the most rigorous traceability solutions, including QR codes and microchips, won't be useful if people don't actually check them as a condition of making their purchases. Imitators can simply counterfeit QR code labels, for example.
。业内人士推荐新收录的资料作为进阶阅读
这些职业彼此之间几乎没有交集，但它们正出现在越来越多女性的人生选择里。她们的职业选择，也正在悄悄改变一些曾经默认的边界。
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