  In this paper, we consider the perturbed Laguerre unitary ensemble described
by the weight function of $$w(x,t)=(x+t)^{\lambda}x^{\alpha}e^{-x}$$ with $
x\geq 0,\ t>0,\ \alpha>0,\ \alpha+\lambda+1 > 0.$ The Deift-Zhou nonlinear
steepest descent approach is used to analyze the limit of the eigenvalue
correlation kernel. It was found that under the double scaling $s=4nt,$ $n\to
\infty,$ $t\to 0 $ such that $s$ is positive and finite, at the hard edge, the
limiting kernel can be described by the $\varphi$-function related to a
third-order nonlinear differential equation, which is equivalent to a
particular Painlev\'e V (shorted as P$_{\rm V}$) transcendent via a simple
transformation. Moreover, this P$_{\rm V}$ transcendent is equivalent to a
general Painlev\'e P$_{\rm III}$ transcendent. For large $s,$ the P$_{\rm V}$
kernel reduces to the Bessel kernel $\mathbf{J}_{\alpha+\lambda}.$ For small
$s,$ the P$_{\rm V}$ kernel reduces to another Bessel kernel
$\mathbf{J}_\alpha.$ At the soft edge, the limiting kernel is the Airy kernel
as the classical Laguerre weight.
