Figure 7

The values of the normalized flux precision function in the different parts of the assumed metabolic network depend significantly on the applied tracer(s). The results of flux estimation: (A) SLE using 100% [1-¹³C]-glucose as the tracer; and from PLEs consisting of: (B) 5 LEs using different mixtures of [U-¹³C]/[U-¹²C]-glucose in each LE, with 20%, 35%, 50%, 65%, or 80% [U-¹³C]-glucose; (C) 5 LEs using partially optimized mixtures of [1-¹³C]/[U-¹²C]/[U-¹³C] glucose for the separate minimization of the approximated variances of the θ ₁₀, θ ₁₂, θ ₁₄, θ ₂₂, θ ₃₁ free fluxes in each LE; (D) 3 LEs using 100% [1-¹³C]-, [3-¹³C]-, or [4-¹³C]-glucose as a tracer; (E) 6 LEs, where 3 of the LEs used in (D) corresponded to partial optimization for θ ₄andθ ₁₂, θ ₁₄, θ ₂₂andθ ₃₁, respectively, and 3 other LEs used the partially optimized mixture of [1-¹³C]/[3-¹³C]/[4-¹³C]-glucose to minimize the approximated variances of the θ ₈, θ ₁₀, θ ₂₆ free fluxes. The values of the normalized flux precision function for all fluxes are indicated by the color-scored grade.