Quick and inexpensive paraffin-embedding method for dynamic bone formation analyses

Amy Porter,Laura R Mccabe,Josselyn Miller,Alexander G Robling,Regina Irwin,Daniel J Horan

doi:10.1038/srep42505

Abstract

We have developed a straightforward method that uses paraffin-embedded bone for undemineralized thin sectioning, which is amenable to subsequent dynamic bone formation measurements. Bone has stiffer material properties than paraffin, and therefore has hereforto usually been embedded in plastic blocks, cured and sectioned with a tungsten carbide knife to obtain mineralized bone sections for dynamic bone formation measures. This process is expensive and requires special equipment, experienced personnel, and time for the plastic to penetrate the bone and cure. Our method utilizes a novel way to prepare mineralized bone that increases its compliance so that it can be embedded and easily section in paraffin blocks. The approach is simple, quick, and costs less than 10% of the price for plastic embedded bone sections. While not effective for static bone measures, this method allows dynamic bone analyses to be readily performed in laboratories worldwide which might not otherwise have access to traditional (plastic) equipment and expertise.

Highlights

The only approach to accurately measure bone formation is to embed and section bone in plastic which requires extensive expertise, specialty equipment, caustic reagents, prolonged plastic infiltration and curing time, and hand operated semi-automated microtomes equipped with special tungsten carbide knives to cut the plastic
To develop a way that labs across the world could readily section mineralized bone for dynamic bone analyses, we focused on using the paraffin embedding method since this is a straight forward approach that is readily available in nearly every histology laboratory
We found that incubation of entire femurs in either 5 or 10% KOH was very effective, but with increasing concentrations the marrow integrity of the section was decreased

Summary

Introduction

The only approach to accurately measure bone formation is to embed and section bone in plastic which requires extensive expertise, specialty equipment, caustic reagents, prolonged plastic infiltration and curing time (typically greater than one week), and hand operated semi-automated microtomes equipped with special tungsten carbide knives to cut the plastic. We developed a method for sectioning mineralized bone that does not require plastic embedding and sectioning. This method can be done with paraffin-based equipment present in a standard histology lab or core

Methods

Results

Conclusion