Laser capture microdissection from formaldehyde-fixated and demineralized paraffin embedded tissues

Laser capture microdissection (LCM) allows for the microscopic procurement of specific cell types from tissue sections that can then be used for gene expression analyses. In conventional LCM, frozen tissues are normally used for molecular analyses. Some recent studies in cancer research demonstrated that it is possible to carry out gene expression analyses of formaldehyde5fixated paraffin embedded (FFPE) material. However, it is still unclear whether LCM from FFPE tissue sections that had been demineralized allows performing quantitative gene expression analyses. Thus, we performed real5 time PCR analysis of specific genes such as dentin sialophosphoprotein (DSPP) in odontoblasts microdissected from engineered dental pulp5like tissues that had been fixed with formaldehyde for 24 hours, demineralized with 10% formic acid for 557 days, and embedded in paraffin. The expression of dentin sialophosphoprotein and 18S mRNA was detected and quantified. This method allows for quantitative gene expression analyses in FFPE tissue samples that had been demineralized.