A novel method to physically expand small biopsy tissue samples could help pathologists predict and diagnose disease more accurately using light microscopy. Researchers at the Massachusetts Institute of Technology, Harvard Medical School, and the Broad Institute developed the method, called expansion pathology (ExPath).

In ExPath, clinical samples are attached to a polymer that swells when wet. An enzyme called proteinase K digests parts of the samples that are not of interest before water is added, swelling the remaining tissues. Expanded to 100 times their original volume, the larger specimens enable 70-nm-resolution imaging on conventional diffraction-limited microscopes. This level of resolution is currently limited to costly electron microscopes, which are rarely used in the clinic.

一种物理上扩大小活检组织样本的新方法可以帮助病理学家使用光学显微镜更准确地预测和诊断疾病。麻省理工学院，哈佛医学院和布罗德研究所的研究人员开发了这种方法，称为扩展病理学（ExPath）。

在ExPath中，临床样品会附着在潮湿时会膨胀的聚合物上。在添加水之前，一种称为蛋白酶K的酶会消化样品中不感兴趣的部分，从而使其余组织肿胀。更大的标本可以扩展到其原始体积的100倍，可以在常规衍射极限显微镜上进行70 nm分辨率的成像。这种分辨率水平目前仅限于昂贵的电子显微镜，在临床上很少使用。