  In this work we discuss the properties of the solutions of the Dirac equation
in presence of an uniform background magnetic field. In particular we focus on
the nature of the solutions, their ortho-normality properties and how these
solutions depend on the choice of the vector potential giving rise to the
magnetic field. We explicitly calculate the spin-sum of the solutions and using
it we calculate the propagator of the electron in presence of an uniform
background magnetic field.
