Louisa McGuinness has been a research technician at the Tissue Bank for almost six years. Here she describes the important role she plays in helping find a cure for Parkinson’s.

What I do can be divided into working with fresh and fixed tissue (which has been preserved in a chemical fixative), and dealing with tissue requests. The vast majority of my time is spent on dealing with fixed tissue. This tends to set the schedule for my typical working week.

Louisa (left) with colleague Regina

First we collect the tissue

This can happen at any time and, as we have to move quickly to ensure that the brain tissue is in the best possible condition, it takes priority over everything else. During work hours, Regina and I take collection in turns. While one of us is in transit, the other prepares the laboratory for the dissection. Out of hours, these tasks fall to members of the on-call team. As we have registered donors throughout the whole country, we could travel anywhere. The furthest I have been to collect tissue is the west coast of Wales, setting off from home about 7am, picking up the tissue early afternoon, and arriving at work about 9pm. That was a rather long day!

Generally, the dissection takes an hour and a half and requires a team of three – a co-ordinator and two assistants. During the dissection, one half of the brain is cut into small blocks and frozen, and the other is placed in fixative so that it can be used to look for changes in the brain due to disease.

The next step

Once the fresh tissue goes into the freezer, it generally remains there until requested for research. For the fixed tissue, however, the work is just beginning. As we continually collect tissue, there is a constant turnover of cases.

Fixed dissections happen on Tuesday mornings. Depending on how many brains are ready to process, we may dissect two in the same session. The neuropathologist cuts the brain into slices, examining it for visible signs of disease and taking samples for further analysis. The rest is cut into blocks and frozen in a similar manner to the fresh tissue. The dissection and the freezing procedures each tend to take about one hour per case.

Before any of the stored frozen tissue can be given out to researchers, it has to be characterised. It’s important to know exactly what type of disease is present in the tissue and how extensive it is. Researchers usually have very specific requests in this regard, and the donor’s next of kin often find this information about their relative helpful too.

Characterisation

This stage involves the samples that the neuropathologist took for analysis during the dissection. I embed the tissue blocks in wax and cut very thin sections, which I collect onto microscope slides ready for staining which helps us look at structures in tissues. We use a standard panel of stains to characterise each case. Dye-based techniques give an overview of the tissue anatomy and show up any obvious abnormalities, or features associated with Parkinson’s disease and other disorders.

Over to the neuropathologist

Once a case is complete, I go through it with the neuropathologist so he can make a preliminary diagnosis and request any additional stains that may prove necessary. We try to schedule case reviews like this once a week, and may screen multiple cases at once. Once I’ve done the extra stains (if there are any), then my part in the process is finished. The neuropathologist will examine the stained slides in detail and write up his findings. The Tissue Bank clinician then writes up an assessment of the donor’s symptoms, based on the information in their medical notes. The neuropathological and clinical assessments form the case report, which includes a diagnosis. The case information is vital for ensuring that we meet researchers’ requirements when supplying tissue.

Helping researchers with tissue requests

Researchers may request fresh-frozen, fixed-frozen or paraffin-embedded tissue. This may be in the form of blocks, or cut sections on slides. Dr Goldring (the Tissue Bank Manager) identifies suitable cases and regions, and passes the details onto either myself or Regina. Fulfilling tissue requests is time-critical and has to fit into the workload to ensure deadlines are met.

The research carried out using the tissue is vital

It isn’t easy telling people what I do for a living. It seems to either start conversations or stop them dead! I’m often asked why do I do this job. Well, there are two main reasons: it’s challenging and it’s important.

It’s challenging because I continue to learn, both about Parkinson’s and about laboratory techniques. I use that knowledge to continue developing the techniques we use.