Presented here is the development for consistently acquiring high-quality dorsal root ganglion cryostat sections.
High-quality mouse dorsal root ganglion (DRG) cryostat sections are crucial for proper immunochemistry staining and RNAscope studies in the research of inflammatory and neuropathic pain, itch, as well as other peripheral neurological conditions. However, it remains a challenge to consistently obtain high-quality, intact, and flat cryostat sections onto glass slides because of the tiny sample size of the DRG tissue. So far, there is no article describing an optimal protocol for DRG cryosectioning. This protocol presents a step-by-step method to resolve the frequently encountered difficulties associated with DRG cryosectioning. The presented article explains how to remove the surrounding liquid from the DRG tissue samples, place the DRG sections on the slide facing the same orientation, and flatten the sections on the glass slide without curving up. Although this protocol has been developed for cryosectioning the DRG samples, it can be applied for the cryosectioning of many other tissues with a small sample size.
The dorsal root ganglion (DRG) contains the primary sensory neurons, the tissue macrophages, and the satellite cells that surround the primary sensory neurons1,2,3,4. It is a key anatomic structure in processing innocuous and noxious signals, and plays critical roles in pain, itch, and various peripheral nerve disorders5,6,7,8,9,10,11,12,13. Although several methods have been developed to dissect DRG tissue from the mouse spinal cord14,15,16, cryosectioning of the DRG tissue remains challenging as the DRG tissue is quite small, and cryostat sections of DRG samples tend to curve into rolls, making it difficult to properly transfer the cryostat sections onto glass slides. However, proper cryosectioning of the DRG tissue is crucial for immunohistochemistry studies and the structure of DRG sensory neurons17,18,19,20,21,22,23. Moreover, as single-cell RNA sequencing results have revealed the remarkable heterogeneity of DRG sensory neurons in both humans24 and mice25, proper cryosectioning of DRG tissue is critical for investigating the functional role of different DRG cells in various physiological and pathological conditions.
Although the tissue-clearing technique has been applied to investigate the 3D reconstruction of the DRG26 as an alternative technique of cryosectioning the DRG, the tissue-clearing technique is time- and labor-consuming. In comparison, cryosectioning of the DRG is quick and relatively easy to perform, and thus it remains to be a key technique for immunohistochemistry and structure studies of the DRG and other regions of the central nervous system. However, obtaining high-quality, intact, and flat cryostat sections onto glass slides remains to be a challenge in neuroscience research because of the tiny sample size of tissues, like the DRG and certain brain regions, and there is no article describing the optimal protocol at this point for cryosectioning small-sized tissue samples, such as mouse DRGs.
This protocol provides an easy, step-by-step technique for cryostat sectioning of the mouse DRG to reliably obtain as many high-quality DRG sections on the slides for subsequent DRG studies. While specifically designed for cryosectioning DRG samples, this technique can potentially be used for cryosectioning various other tissues with a small sample size.
This protocol provides an easy step-by-step procedure for cryostat sectioning of the mouse DRG to obtain high-quality DRG sections on slides reliably.There are four critical steps in this protocol. First, the DRG sample and the tweezers must be dry before putting the DRG sample onto the base OCT. Any liquid surrounding the DRG sample will form an ice shell around it, resulting in DRG sections separating from the OCT and curving up. Second, if the aluminum block does not have a mark, or if the base OCT covers the mark, it…
The authors have nothing to disclose.
None.
Avertin | Sigma-Aldrich | T48402-25G | Anesthetize animal |
Epredia Cryotome Cryostat Cryocassettes, 25 mm dia. Crosshatched | Fisherbrand | 1910 | Hold the OCT section at the bottom |
Ergo Tweezers | Fisherbrand | S95310 | Using the end of a tweezer to gently touch the bottom (6 o’clock) of the section so that it sticks to the platform surface to prevent the section from curving back in a roll |
Fisherbrand Superfrost Plus Microscope Slides | Fisherbrand | 1255015 | To collect the DRG section |
Marking pens | Fisherbrand | 133794 | Mark the orientation of base OCT |
Scigen Tissue-Plus O.C.T. Compound | Fisherbrand | 23730571 | Embedding medium for frozen tissue specimens to ensure optimal cutting temperature (O.C.T.). |