Background--how it works
BCA uses an indirect method to indicate the amount of protein. The sample interacts with BCA extraction buffer, reducing cupric ions to cuprous ions. Cuprous ions can then combine with BCA working agents and form purple color. The intense of purple color has a positive relationship with the amount of protein present in the sample. As such, by comparing sample color with a serious of standard protein solution, it is able to determine the amount of protein.
Objective
Use bicinchonini acid (BCA) to determine the protein concentration in tuna sample.
Result
Objective
Use bicinchonini acid (BCA) to determine the protein concentration in tuna sample.
Result
Comments
According to our result, the protein in the tuna sample is much lower. In the nutrition label, the protein concentration is 21.05%, while in our result the concentration is 2.26%. The reason for the difference may be:
1. The concentration for the extraction buffer
2. The extraction buffer fail to dissolve all the protein from tuna sample
3. The protein loss at each step, for example blending, centrifuge and filtration.
BCA is not a stable as protein measurement, as BCA extraction buffer and working agent are influenced by other reducing compounds like ions, sugars. As such, the result for protein concentration is usually higher than the actual sample, which doesn’t fit with our expectation.
Modification
In order to get a better result
a) Use more extraction buffer or let buffer interact with tuna for a longer time
b) Longer time interval (10, 15, or maybe 20, etc.)
c) Have more series of dilution (10^-8 or 10^-10)
d) Use other extraction methods as control
e) More trials
Other protein Measurements
According to our result, the protein in the tuna sample is much lower. In the nutrition label, the protein concentration is 21.05%, while in our result the concentration is 2.26%. The reason for the difference may be:
1. The concentration for the extraction buffer
2. The extraction buffer fail to dissolve all the protein from tuna sample
3. The protein loss at each step, for example blending, centrifuge and filtration.
BCA is not a stable as protein measurement, as BCA extraction buffer and working agent are influenced by other reducing compounds like ions, sugars. As such, the result for protein concentration is usually higher than the actual sample, which doesn’t fit with our expectation.
Modification
In order to get a better result
a) Use more extraction buffer or let buffer interact with tuna for a longer time
b) Longer time interval (10, 15, or maybe 20, etc.)
c) Have more series of dilution (10^-8 or 10^-10)
d) Use other extraction methods as control
e) More trials
Other protein Measurements