AF4 may refer to:
*
AF4/FMR2 family member 1, a human protein
*
Asymmetric flow field flow fractionation Asymmetrical flow field-flow fractionation (AF4) is most versatile and most widely used sub-technique within the family of field flow fractionation (FFF) methods. AF4 can be used in aqueous and organic solvents and is able to characterize nanoparti ...
, a method for polymer characterization
* AF4: an EEG electrode site according to the
10-20 system
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