  In this paper, the gauge choices in general spherically symmetric spacetimes
have been explored. We construct the gauge invariant variables and the master
equations for both the Detweiler easy gauge and the Regge-Wheeler gauge,
respectively. The particular cases for $l=0,1$ are also been investigated. Our
results provide analytical calculations of metric perturbation in general
spherically symmetric spacetimes, which can be applied to various cases,
including the Effective-One-Body problem. A simple example is presented to show
how the metric perturbation components are related to the source perturbation
terms.
