We describe a method for the rapid quantification of serum apolipoprotein B48 using a commercially available anti-apolipoprotein (apo)B antiserum and compare it to analytical sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with coomassie blue R250 staining. The method described here eliminates the need for de-lipidation of samples and only requires a one-step overnight ultracentrifugation. Western-blotting and enhanced chemiluminescence (ECL) visualization of proteins was approximately 10 times more sensitive than coomassie staining and generally took no longer to complete than staining/destaining of SDS-PAGE gels. The sensitivity of the antiserum/ECL technique enabled quantitation of fasting apolipoprotein B48 which could not be resolved by SDS-PAGE and Coomassie staining.