Tag Archives: Clinical Trials

Inside a Clinical Trials lab at UCLH: Part II, Flow Cytometry

by Ridwaan Joghee

During my In2ScienceUK placement I’ve also learnt the process of ‘flow cytometry’. To begin cytometry is the quantifiable analysis of cells and cell systems. Prevalent examples are flow cytometry and image cytometry, which are primarily optical methods.

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The flow cytometer works by counting and analyzing the size, shape and properties of different cells within a heterogeneous population.

Firstly, before using a flow cytometer you have to prepare your test-tube samples which contain a suspension of cells or tissues. This will include staining your samples with ‘trypan blue’, this is so the laser can observe different parts of the cell and can analyze in detail.

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The flow cytometer then sucks up the fluid from the test-tube. The fluid is then mixed with a saline solution. Inside the cytometer there is a laser which analyses each cell. Each cell (single file) passes through the laser. The laser then carefully analyses the cells. This analysis means we can differentiate cells size, shape and properties into different groups.

There will then be data produced on the computer screen, we can use a univariate histogram to display the data. A correlation will then be produced between two constraints using a bivariate histogram, or cytogram, in the arrangement of a dot, contour or density plot. This process is fundamental for scientists since they’ve to know if patients have enough red or white blood cells in their system. From this quantitative analysis of cells, we can come to a conclusion that certain cells are lacking and a further conclusion can be drawn about the patient, this narrows the possible problems of the patient, so the actual problem becomes clear.

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Ridwaan was supervised by Caroline Cook at the NIHR/Wellcome UCLH Clinical Research Facility

Inside a Clinical Trials lab at UCLH: Part I, Centrifuges

By Ridwaan Joghee

During my In2ScienceUK placement at UCL/h for clinical trials I’ve learnt what research scientists do in their everyday working life. On the first day of my placement I’ve learnt a basic technique on how to use a centrifuge, in my opinion scientists entirely depend on this piece of equipment.

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The main function for a centrifuge is to put test-tubes (which usually contain blood in our lab) in rotation around a fixed axis, applying a potentially strong force perpendicular to the axis of spin. I’ve also learnt that you cannot just place test-tubes randomly in the metal buckets. Instead you’ve to balance the test-tubes anti-parallel from the opposite bucket. If you fail to do so the test tubes will break and the contents of it (usually blood) will cause a spillage and you could even get HIV by doing so!

Once the blood has been centrifuged you’ll notice that the plasma is detached from the red-blood cells. This plasma needs to then be extracted out by using a pipette. This process must be done extremely carefully as you may damage the separation layer and re-mix the two components again. If occurs, you’ll have to centrifuge the test tube again.

Plasma contains a mixture of water, sugar, fat, protein, and salts. The main job of the plasma is to transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones, and proteins that help maintain the body’s fluid balance. Therefore, the plasma contains supplementary genetic information about the patient which can then be analyzed. This is so scientists can see what specific nutrients or hormones (for example) the patient lacks.