Thesis points to blood tests as a future alternative to biopsies

A doctoral thesis from Tallinn University describes a method that could improve future blood tests and help reduce the need for tissue biopsies, ERR reports. Doctors often take a piece of living tissue to understand what is happening inside a tumour or another damaged organ.

Researcher Danilo Mladenović’s approach focuses on vesicles, tiny particles released by cells that carry proteins and fragments of genetic information. Changes in these particles could provide clues about what is happening in the body.

To study vesicles in blood plasma, researchers must separate them from similar fat particles that can distort test results. Mladenović lowered the plasma’s pH to 5.5 using hydrochloric acid. The acidic conditions broke down lipoproteins, while the vesicles remained intact and could be collected more easily using a centrifuge.

The method increased the yield of vesicles by 3.3 times compared with previous approaches and reduced the proportion of interfering fat particles by 61 percent. Mladenović hopes the technique could save time in hospitals and make new blood tests more accurate.

His thesis also compared two advanced machines used to count vesicles. The devices can produce different results because they assess particle size and number by different standards, and less sensitive machines may miss smaller vesicles.

Mladenović developed standards and checking methods using fluorescent nanobeads as a common measure. He linked the beads’ light intensity to a set number of antibodies, helping bring measurements from the two machines onto the same scale.