By WWII, scientists had already begun looking at alternative gelling substances for routine use in bacteriology, but concluded that agar was still better as it is both firmer and easier to handle. Today, some specialized microbiology applications use the colloid carrageenan (extracted from red seaweed Chondrus crispus, or “Irish Moss”), a more transparent and less auto-fluorescent alternative to agar (agar emits its own background fluorescence when excited by light). However, for routine bacteriological use, carrageenan is more difficult to dissolve, requires higher concentrations, can degrade at high temperatures, and forms weaker gels, which may result in puncturing its surface during the plating of cells.
我当了30年文学刊物编辑，见过许多憋着劲儿要“一鸣惊人”、结果连第一段都画不上句号的作者。写作面对的最狠的敌人是什么？不是文笔差，不是没想法，而是那个在你耳边嘀咕“这不行、那不够”的完美主义小鬼。它让你写了三句删两句，让你总觉得这句、这段“没写好”，最后留下一个完不成的“作品”，或者什么也没留下。
，推荐阅读搜狗输入法2026获取更多信息
Gemma HandyBusiness reporter
统一使用：即查即用的数据集能力
В России ответили на имитирующие высадку на Украине учения НАТО18:04