Topic 6 Techniques Flashcards
What is the ISO-10993?
It’s a guide for required tests on medical devices and planning of these biological evaluations.
What is the ISO 10993 biocompatibility matrix?
It helps to select appropriate toxicity tests.
How is coagulation often measured?
An assay (e.g. ELISA) for coagulation proteins like FPA (fibrinopeptide) or TAT (thrombin-antithrombin III complex).
How is hematology often measured?
Measure how much blood cell damage the biomaterial cause. Can be measued with electric particle counting
Why is hematology measured?
If the blood flow is turbulent and not laminar this can damage blood cells and induce the blood coagulation cascade, maybe because the proteins are in closer contact.
What’s the Chandler Loop model?
You fill tubes of different materials with non-heparinized blood, then they are put in an incubator and rolled. After some time the amount of remaining platelets in the blood, granule content and material surface are analyzed.
What is SIMS and what do you measure?
Secondary ion mass spectrometry - you focus an ion beam on a surface that “sputter” away some of the surface molecules. That also fragmentize them into secondary ions and they are then measured by a detector and a m/z diagram can be made. You analyse the surface molecules.
What is surface functionalized chromatography?
You separate biomolecules based on charge and size The surface of the beads inside the chromatograph is functionalized for that. Very sensitive and can distinuish between same molecule but diff. fragments of it.
What’s reflectance fourier transform - infrared spectroscopy (ATR-FTIR)?
You analyse which proteins been absorbed to the surface by refracting infrared light through a ATR crystal close together with the sample surface. The molecules vibration and rotation will affect which light is absorbed by the detector.
What is surface plasmon resonance (SPR)?
Light hit with a specific resonance angle a gold surface with pre-immobilised dextran. The detector that recieve the reflected light can see if there has been a change in the electric oscillation of the gold particles as proteins absorb on the dextran. As low as 2-3 protein layers can be detected.
What is Atomic force microscopy? AFM
Two sample tips with different width are used to measure the surface morphology as it can be detected how much the tip interacts with the surface atoms.
Name 4 common protein assays
Colorimetric assays (spectrometer, enzyme induced color), fluorescence assays, ELISA and western blotting (SDS-PAGE)
Briefly describe ELISA
A primary antibody is coupled to a surface in a well. The protein of interest absorb to it and then a secondary antibody bind to the protein and this AB have a covalently linked enzyme for substrate. The substrate is added and this reacts with the enzyme to give rise to fluorescense.
How can cells be easily visualized?
They can be seen in microscopy when stained and by using different imaging methods. Can be stained by immunohistochemistry (ABs with fluorophore) or quantum dots or GFP. Different miroscopes can be used such as confocal microscopy, FRET etc.
How can cell adhesion be measured?
You can try to remove them by shear stress from a liquid.
