Back in his day, a few scientists had been tinkering with staining tissues, especially with a compound called carmine — a red dye derived from the scales of a crushed-up insects.

在他那个时代，一些科学家一直在修补染色组织，特别是一种叫做胭脂红的化合物——一种从压碎的昆虫鳞片中提取的红色染料。