# protein estimation colorimetry.. preferred range.. - statistically more precise & accurate? (Jun/04/2008 )

hii all.. needed to clear this basic confusion..

for protein estimation by colorimetric methods.. what is the preferred range.. higher side or lower?

when i use higher range (eg 1-2 mg/ml) i get higher OD values and precision in those values is expected to be higher. accuracy too.. proabably.

wheni use a microplate method (0.125 mg/ml- 1) i get lower OD values.. may not be as precise.. at least at the lower side of the range.. but my lowest point in the graph of OD vs concentration for unknown concentraion calculation.. is near the intercept. it being near the intercept.. the precision in the intercept value is increased.. which directly influences the concentration of the unknown. but my OD values at the lowest point are low.. and have high varition.

statistically / practically.. what do u think wil give me more precise/accurate results? higher / lower range.. i think the higher would be better to work with.. but wiht the lower range.. my lowest point shows variation.. so one option i have is to remove the lowest point. but that may have an effect on the intercept values and increase imprecision.. what say? thanks!!

for protein estimation by colorimetric methods.. what is the preferred range.. higher side or lower?

when i use higher range (eg 1-2 mg/ml) i get higher OD values and precision in those values is expected to be higher. accuracy too.. proabably.

wheni use a microplate method (0.125 mg/ml- 1) i get lower OD values.. may not be as precise.. at least at the lower side of the range.. but my lowest point in the graph of OD vs concentration for unknown concentraion calculation.. is near the intercept. it being near the intercept.. the precision in the intercept value is increased.. which directly influences the concentration of the unknown. but my OD values at the lowest point are low.. and have high varition.

statistically / practically.. what do u think wil give me more precise/accurate results? higher / lower range.. i think the higher would be better to work with.. but wiht the lower range.. my lowest point shows variation.. so one option i have is to remove the lowest point. but that may have an effect on the intercept values and increase imprecision.. what say? thanks!!

See result no. 2

http://search.vadlo.com/b/q?sn=158621799&a...range&rel=0

..

for protein estimation by colorimetric methods.. what is the preferred range.. higher side or lower?

when i use higher range (eg 1-2 mg/ml) i get higher OD values and precision in those values is expected to be higher. accuracy too.. proabably.

wheni use a microplate method (0.125 mg/ml- 1) i get lower OD values.. may not be as precise.. at least at the lower side of the range.. but my lowest point in the graph of OD vs concentration for unknown concentraion calculation.. is near the intercept. it being near the intercept.. the precision in the intercept value is increased.. which directly influences the concentration of the unknown. but my OD values at the lowest point are low.. and have high varition.

statistically / practically.. what do u think wil give me more precise/accurate results? higher / lower range.. i think the higher would be better to work with.. but wiht the lower range.. my lowest point shows variation.. so one option i have is to remove the lowest point. but that may have an effect on the intercept values and increase imprecision.. what say? thanks!!

better is lower as too high protein may be near saturation of assay