Figure 3.

Analysis of mucin size distribution by means of rate-zonal centrifugation. The sample was layered onto preformed 6- to 8-M guanidinium chloride gradients and centrifuged for 2.5 hours at 40,000 rpm and 15°C. Fractions (1 mL) were unloaded from the top of the tube and immunoblotted for MUC5AC and MUC5B by using mucin-specific antisera. The average size distributions for MUC5AC (A) and MUC5B (B) are shown. Each value represents the mean, with SD error bars. ● = Control subjects (n = 4); ▪ = children with asthma acute exacerbation (n = 7); and ▲ = children with acute asthma at recovery. Fraction 1 = lowest density; fraction 12 = highest density.