Low-temperature resin embedding of the whole brain for various precise structures dissection

Jiaojiao Tian; Yingying Chen; Tao Jiang; Xueyan Jia; Hui Gong; Xiangning Li

doi:10.1016/j.isci.2023.106705

Low-temperature resin embedding of the whole brain for various precise structures dissection

iScience. 2023 Apr 20;26(5):106705. doi: 10.1016/j.isci.2023.106705. eCollection 2023 May 19.

Authors

Jiaojiao Tian^{1

2}, Yingying Chen¹, Tao Jiang³, Xueyan Jia³, Hui Gong^{1

3}, Xiangning Li^{1

4

3}

Affiliations

¹ Britton Chance Center and MoE Key Laboratory for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
² Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China.
³ Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, Chinese Academy of Medical Sciences, HUST-Suzhou Institute for Brainmatics, JITRI, Suzhou 215125, China.
⁴ Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou 570228, China.

Abstract

Resin embedding combined with ultra-thin sectioning has been widely used in microscopic and electron imaging to acquire precise structural information of biological tissues. However, the existing embedding method was detrimental to quenchable fluorescent signals of precise structures and pH-insensitive fluorescent dyes. Here, we developed a low-temperature chemical polymerization method named HM20-T to maintain weak signals of various precise structures and to decrease background fluorescence. The fluorescence preservation ratio of green fluorescent protein (GFP) tagged presynaptic elements and tdTomato labeled axons doubled. The HM20-T method was suitable for a variety of fluorescent dyes, such as DyLight 488 conjugated Lycopersicon esculentum lectin. Moreover, the brains also retained immunoreactivity after embedding. In summary, the HM20-T method was suitable for the characterization of multi-color labeled precise structures, which would contribute to the acquisition of complete morphology of various biological tissues and to the investigation of composition and circuit connection in the whole brain.

Keywords: Biological sciences research methodologies; Methodology in biological sciences; Neuroscience; Techniques in neuroscience.