  The AGT conjecture relates \mathcal{N}=2 4d SUSY gauge theories to 2d CFTs.
Matrix model techniques can be used to investigate both sides of this relation.
The large N limit refers here to the size of Young tableaux in the expression
of the gauge theory partition function. It corresponds to the vanishing of
Omega-background equivariant deformation parameters, and should not be confused
with the t'Hooft expansion at large number of colors. In this paper, a saddle
point approach is employed to study the Nekrasov-Shatashvili limit of the gauge
theory, leading to define beta-deformed, or quantized, Seiberg-Witten curve and
differential form. Then this formalism is compared to the large N limit of the
Dijkgraaf-Vafa beta-ensemble. A transformation law relating the wave functions
appearing at both sides of the conjecture is proposed. It implies a
transformation of the Seiberg-Witten 1-form in agreement with the definition
specified earlier. As a side result, a remarkable property of \mathcal{N}=2
theories emerged: the instanton contribution to the partition function can be
determined from the perturbative term analysis.
