Quantitative determination of titin and nebulin in poultry meat by SDS-PAGE with an internal standard.

The method of quantitative determination of titin and nebulin in chicken meat by SDS-PAGE electrophoresis technique was developed by application of β-galactosidase as the internal standard. The method was tested first on marker protein samples of known concentrations (myosin, transferrin, glutamic dehydrogenase) and then the method was used in the determination of titin and nebulin content in chicken meat. The method demonstrated high accuracy, confirmed by correlation coefficient 0.91÷0.99. Two gel analysis techniques, i.e. scanning and densitometry were also compared. By the use of marker proteins as well as titin and nebulin, higher accuracy and precision were achieved in scanning than in the densitometric technique. Recoveries of three marker proteins were between 93 and 102% for the technique of the scanning of the gel and between 99 and 116% for the densitometry.