A simple method for determination of pepsinogen in bovine serum and plasma.

Calf serum pepsinogen can be determined by radial diffusion in a casein-containiing agarose gel prepared at pH 8.2 and afterwards immersed in a BaGla-containing buffer, pH 2.4, whereby the casein is precipitated homogeneously. Serum samples are placed in wells in the gel, and at the low pH pepsinogen present in the samples will be activated and the casein digested, whereby transparent, circular zones are formed in the otherwise opaque gel. The diameter of these zones can be measured directly and used as an expression of the serum pepsinogen level. On analysis of a number of sera from calves with or without ostertagiasis a positive correlation was found between the results obtained by this method and conventional absorption photometry (r = 0.87, n = 55).