Does the magnetic field of a magnetic stirrer in an optical aggregometer affect concurrent platelet aggregation?

Abstract

Platelets are subjected to extremely low frequency electromagnetic fields during standard aggregometry measurements owing to the use of a magnetic stir bar in the instrument. This study evaluates the effects of this magnetic field exposure on platelet aggregation by comparing the results obtained in a modified aggregometer. Blood samples from healthy volunteers were anticoagulated using citrate or heparin. Platelet-rich plasma (PRP) samples were prepared. A mechanical stirring device was attached to the aggregometer instead of the magnetic stir bar system. The PRP samples were stirred using a stirring rod tip that did not produce any magnetic fields in one channel of the aggregometer; in the other channel, a stirring rod carrying a small magnet at its tip was used. As a result, a magnetic field in the extremely low frequency range and in the amplitude range of 1.9-65 mT was applied to the platelets assigned to the channel where the magnetic stirring rod tip was used. Aggregation was induced using adenosine diphosphate (ADP), collagen, or epinephrine. The slopes, maximum aggregation values, and areas under the aggregation curves were compared between the magnetic and neutral stirring rod tip groups. For samples stirred with the magnetic stirring rod tip, a significant decrease was observed in 12 of the 14 parameters evaluated for aggregations induced with ADP or collagen compared to the neutral stirring rod tip, regardless of the method used for anticoagulation. This observation indicates that the magnetic stir bars used in standard aggregometry may significantly alter aggregation parameters and platelets may be possible targets of electromagnetic fields.

Which waters hydrate best? A study using brine-shrimp cysts (Artemia franciscana)

“…We investigated different stirring speeds of 0, 80, and 400 rpm with magnetic stirring. To compare magnetic stirring with mechanical stirring, we also conducted an experiment using a home-made overhead stirrer, which minimized the impact of magnetic field that can be generated by magnetic stirring, and potentially improve cyst hydration (Yuriy et al 2010, Sagdilek et al 2013). Results are shown in Figure 3 .…”