[Spectrophotometric determination of the quantity of protein in standard biological suspensions]

A combined method for spectrophotometric measurement of protein amount for conventionally isolated biological suspensions is suggested. The method is based on the comparison of data on the optical density of a suspension at 280-290 nm with the result of a single colorimetric determination. For the membranes of sarcoplasmic reticulum and mitochondria it has been shown that the combined spectrophotometric method gives possibility to shorten the time of measurement, has high specificity and sensitivity and compares favourably with usual colorimetric methods in relation to accuracy. A calibration chart was obtained for conventionally isolated "Wistar" rat liver mitochondria.