& Data Analysis Protein gel analysis Keeping a lab notebook
Writing research papers Dimensions & units Using figures
(graphs) Examples of graphs Principles of microscopy Solutions &
dilutions Fractionation & centrifugation Radioisotopes and
detection Biuret Protein Assay Considerations for use The
principle of the biuret assay is similar to that of the Lowry,
however it involves a single incubation of 20 min. There are
very few interfering agents (ammonium salts being one such
agent), and Layne (1957) reported fewer deviations than with the
Lowry or ultraviolet absorption methods. However, the biuret
assay consumes much more material. The biuret is a good general
protein assay for batches of material for which yield is not a
problem. The Bradford assay is faster and more sensitive. Under
alkaline conditions substances containing two or more peptide
bonds form a purple complex with copper salts in the reagent. In
addition to standard liquid handling supplies a visible light
spectrophotometer is needed, with ma