A comparison of five of the methods commonly used to measure protein concentrations in fish sera

Abstract

The concentration of protein in the sera of rainbow trout, Salmo gairdneri, brown trout S. trutta and Atlantic salmon S. salar has been measured by six standard techniques viz refractometry, copper sulphate specific gravity, automated and manual biuret, optical density and Lowry et al. phenol reagent and the results compared. Good correlation was obtained in most cases and interconversion formulae are given between each method in the three salmonid species. The concentrations obtained with the refractometer and optical density methods were approximately one and a half times those obtained with the others.

Immunoglobulin concentration in Atlantic cod, Gadus morhua L., serum and cross‐reactivity between anti‐cod‐antibodies and immunoglobulins from other species

“…tIn another paper by the same authors (Alexander & Ingram, 1980) protein concentrations of approximately 38-39 mg ml-' are reported when estimated by the biuret method, which is the most common in the other studies. Thus the proportion of Ig will be approximately double to that reported in the paper.…”

Refractometry as an alternative to the biuret method for measuring total serum proteins in Podocnemis expansa (Podocnemididae) and Phrynops geoffroanus (Chelidae)

“…Due to the ease, speed of procedure, and small amount of material required, refractometry has been widely used to determine the total protein concentration in bovines, canines, equines, felines, fish, wild mammals, and birds (De Smet 1978;Alexander and Ingram 1980;George 2001). …”

Compared accuracy of two enzyme linked immunosorbent assay (ELISA) methods performed with polyclonal antibodies to measure immunoglobulin levels inPlatichthys flesusL. 1758 (Flounder)

“…Again, this may be due to technical di#erences. However, it may also be due to environmental factors in maintaining the fish as reported by Alexander & Ingram (1980), Laudan et al (1987) and Takemura (1993).…”