This assay has high sensitivity and excellent specificity for detection of Complement Component 4. No significant cross-reactivity or interference between Complement Component 4 and analogues was observed. Sample types: serum, plasma and other biological fluids. Range: 6.25-400 ng/mL. Sensitivity: 2.74 ng/mL. Intra-assay Precision (Precision within an assay): 3 samples with low, middle and high level Complement Component 4 were tested 20 times on one plate, respectively. Inter-assay Precision (Precision between assays): 3 samples with low, middle and high level Complement Component 4 were tested on 3 different plates, 8 replicates in each plate.CV (%) = SD/meanX100;Intra-Assay: CV<10%;Inter-Assay: CV<12%. Time: 3 hours