Cavitation, membrane transfer, and molecular response

Two topics are discussed in the following. First, red cell lysis and membrane transfer are primarily caused by cavitation since they are suppressed by excess hydrostatic pressure in the exposure vessel. It was additionally proposed that shock waves destroyed red blood cells directly at excess pressure above 10 MPa when cavitation was absent. When this was re‐examined with a different pressure chamber with 10 and 20 MPa excess pressure, there was no increased red cell lysis and no direct action of shock waves was found. Second, it was long thought that the transfer of fluorescein dextran into cells was a good method to co‐transfer another molecule. Dextran and the other substance had to be dissolved well in a defined molecular ratio and cells with a defined number of dextran molecules recovered by flow sorting contained also a defined number of the other molecule. The attempt to apply this approach for various numbers of molecules of a ribosome inactivating protein revealed, however, an inconclusive result.