Sensitivity of SNaPshot assay for the (A) CP and the (B) HC-Pro primers. Both graphs demonstrate a linear relationship for each SNP (individual lines; see Figure 1 for product names). The sensitivity of the assay was determined by identifying the pmoles that correspond to 800 FU using the linear equation of the SNP with the steepest slope (C55 and H45). Linear equations: y = 336285x-475.19 and y = 285041x-1239, CP and HC-Pro, respectively. CP, coat protein; FU, fluorescent units, HC-Pro, helper-component protease, SNP, single nucleotide polymorphism.