Is it possible to re-identify a particular electron? are there identity conditions for electrons? I think that being able to formulate a clear identity criterion for the objects it deals with is important for any theory. 
For example, set theory starts by the extensionality axiom telling that 
  set A is identical to set B iff A and B have exactly the same elements. 

[ In the same way, arithmetics says that number a and number b are equal (i.e. are exactly the same number) iff
                               a-b = 0 ] 

Consequently, I'm led to ask the question: what are the identity conditions for electrons? 
In which case and under which conditions (sufficient and necessary) can I say that this electron e2 that I observe now is the same electron as electron e1 I observed previously?
 A: Subatomic particles are in principle indistinguishable. The quantum mechanical mathematics used to describe them in interactions explicitly contains that fundamental indistinguishability and provides a testable and falsifiable account of reality at the quantum level. That account is in stunningly accurate agreement with experiment; examples of such results can be found in Richard Feynman's popular book about QED (quantum electrodynamics).  
This illustrates at least one fundamental difference between philosophy and physics. 
A: All electrons, like all elementary particles, are completely identical and thus indistinguishable. They can be in different quantum states, but you cannot be sure which electron is in which state.
The reason that all electrons are identical is that they are all quanta of one quantum field describing electrons and positrons that extends throughout the universe. There is just one quantum field for each kind of elementary particle/antiparticle. Physics is not about the $10^{80}$ particles in (the observable part of) our universe; it is about the 17 (by one way of counting, in today’s Standard Model) quantum fields in our universe.
The identicality of fermions such as electrons is the basis for the Pauli exclusion principle. Without it, chemistry and biology as we know them would not be possible because atoms would have all of their electrons in the ground state. The identicality of bosons such as photons is the basis for technology such as lasers.
