“Tissue over- and underfixing, crosslinking of biomolecules and lack of standardization can lead to loss of morphology and poor quality histological preparations,” according to Lynne Rainen, Ph.D., scientific director at PreAnalytiX, a Qiagen/BD company. Dr. Rainen discussed her company’s PAXgene tissue system, which is designed to overcome the drawbacks of conventional tissues processing.
The PAXgene tissue system’s first step involves the use of a special container for fixation and stabilization of the tissues under a standardized set of conditions. This allows the formalin-free preservation of nucleic acids along with the histomorphology of the tissues. Dr. Rainen argues that there are marked advantages to her company’s technology.
“It provides details of the histology comparable to classic H&E staining, it is compatible with immunohistochemical applications, it preserves DNA for PCR-based applications, and it allows purification of all nucleic acids from one sample,” she said.
Whereas standard fixation technologies may allow PCR amplification to take place, the company’s studies have shown much better PCR response with the PAXgene system, Dr. Rainen noted. She said that the system is particularly effective at copurification of small RNAs.
“The excellent preservation of RNA samples means that the system can be used for quantitative downstream measurements of message content in tissues, enabling molecular pathology testing at a level of accuracy not previously attainable,” Dr. Rainen concluded.