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Challenges with Existing Methods
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Kjeldahl, Dumas: not selective to protein;
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True Protein Kjeldahl: non‐protein, nitrogen‐containing
compounds may precipitate or form complex with
precipitated protein
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Amino Acid: Inaccurate quantitation due to variable
recovery of amino acids
•
Copper, Dye‐Binding: other constituents besides proteins
form complexes
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Lack of Standards
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Protein biosynthesis is expensive, time‐consuming, not robust
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Proteins samples vary widely and usually include multiple proteins
Things to Consider
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Should method address qualitative or quantitative aspect?
Or, both?
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Should ranges be established for quantitative methods?
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Are multiple methods required as part of orthogonal
approach due to complex nature?
•
How to define which proteins need to be analyzed, since
samples usually contain multiple proteins, and even the
same protein species can be diverse between samples?
•
How to overcome the challenge of obtaining adequate
reference material standards?