Application of methacarn fixation for genetic analysis in microdissected paraffin-embedded tissue specimens

Recent advances in microdissection have succeeded the molecular biological approaches on specific cells of interest within tissue specimens by overcoming the obstacle of tissue complexity. Recently, we found that methacam is suitable for analysis of RNA, protein, and genomic DNA in small tissue samples using paraffin-embedded tissue (PET) sections in conjunction with microdissection technique. By application of sensitive quantitation methods, such as those utilizing fluorescent dyes specific for RNA or protein, molecules of small quantity can be normalized between samples, and thus quantitative expression analysis for RNA or protein can be applied in microdissected small tissue specimens. In addition, methacarn-fixation extends its availability for genomic DNA analysis in terms of target fragment size and number of microdissected cells required. Paraffin embedding permits ease of handling tissues that extend the availability of methacarn fixation for genetic analysis in large-scale experiments. In addition, considering its advantages for immunohistochemistry, tissue embedding after methacarn-fixation should be recommended as a valuable approach for routine application possibly in combination with targeted genetic analysis of immunophenotypically defined cell populations. In combination with techniques such as expression library construction, microarray and subtractive hybridization or differential display, microdissection will permit the establishment of “genetic fingerprints” of specific cellular areas.