qPCR Relative Expression (ΔΔCt)

Calculate fold change in gene expression using the Livak method.

Experimental Group (Treated)

Target Gene (Ct) Reference Gene (Ct)

Control Group (Untreated)

Target Gene (Ct) Reference Gene (Ct)

Fold Change (2^-ΔΔCt)

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The Livak Method

This model assumes that both the target and reference genes are amplified with efficiencies near 100% (or that their efficiencies are equal). A fold change > 1 indicates upregulation relative to the control, while < 1 indicates downregulation.

ΔCt (Treated) = Ct(Target) - Ct(Ref)
ΔCt (Control) = Ct(Target) - Ct(Ref)
ΔΔCt = ΔCt (Treated) - ΔCt (Control)
Fold Change = 2^(-ΔΔCt)