Quality tissue cutting for Human Protein Atlas Project

The Human Protein Atlas Project is using the Thermo Scientific HM355S automated microtome and Section Transfer System to create high-quality tissue sections during tissue microarray (TMA) production.

As part of the project, and as an external TMA production service, the Uppsala-based Science for Life Laboratory (SciLifeLab) tissue profiling group has cut more than 200,000 slides from over 1400 TMAs to date. To achieve this, SciLifeLab required a versatile microtome that would accommodate a variety of tissue types, with a choice of manual and mechanised cutting. The HM355S met these needs.

When sectioning TMAs, the greatest risk of valuable tissue loss or damage can occur during transfer to a water bath. For this reason, the SciLifeLab group uses the automated Section Transfer System alongside the HM355S to eliminate such risks. This 'waterfall' system stretches sample ribbons as they are cut and simultaneously transports them safely from the blade into the integrated circulating laminar flow bath. From here, sections can be readily mounted onto glass slides.

The actual composition of a tissue array can also cause complications when sectioning. An example is cancer tissues, which are generally homogenous where normal tissues have greater heterogeneity.

“To overcome issues with mixed tissue composition, our experts group tissues into those with similar texture and hardness when sectioning to make set-up easier and improve workflow,” explained Dr Caroline Kampf, SciLifeLab and HPA site director.

“The HM355S microtome gives us the high-quality, reproducible sections that we need for analysing the TMAs. The different cutting modes provide greater control over section generation, which is especially useful when sectioning a range of specimens of differing consistency.”

A further sectioning consideration at SciLifeLab Uppsala is the fact that the TMAs are paraffin embedded. Consequently, the Thermo Scientific Cool Cut peltier-cooled attachment is used on the group’s microtomes to prolong the cutting period by maintaining a cool block temperature. By using such a cooling tool, 50 TMA sections can be cut consecutively in 50 min without the need to remove and re-cool the block on ice. This ensures effective throughput and efficient laboratory operation.

“Due to the enormity of profiling the human proteome, our team holds a great deal of practical experience in TMA production for the HPA and, in fact, we now offer an external TMA production, sectioning and scanning service,” said Dr Kampf.

“Consequently, our experts handle many different types and combinations of tissues for which safe, efficient and high-quality sectioning, provided by the Thermo Scientific HM355S and associated attachments, is fundamental to our high-throughput, high-quality TMA production.”

For more information, visit www.thermoscientific.com/pathology and http://tinyurl.com/SciLifeLab.