Linear Range Of Assay

That is we optimize the range of the assay.

Linear range of assay.

Reportable range includes analytical measurement range amr and clinically reportable range crr. If a linear relationship between analyte concentration and method response is not obtained it will be impossible to report quantitative patient results by that method. A linear range can be found from the linearity assessment experiments however the criteria for a linear range can be different. The linear range is that range of input or output values for which an electronic amplifier produces an output signal that is a direct linear function of the input signal.

That is the output can be represented by the equation. Few if any protein assays are perfectly linear over the entire useful assay range. Reportable range is the functional range of an assay over which the concentrations of an analyte can be measured with acceptable accuracy and precision. The bradford assay a colorimetric protein assay is based on an absorbance shift of the dye coomassie brilliant blue g 250 the coomassie brilliant blue g 250 dye exists in three forms.

As long as the appropriate curve fit is used an assay does not need to be linear to be accurate. We generally try to work within the linear range of an assay that is where absorbance is directly proportional to concentration. The method is based on the proportional binding of the dye coomassie to proteins. Linearity of dilution is determined by measuring multiple dilutions of known positive samples by elisa.

Under acidic conditions the red form of the dye is converted into its blue form binding to the protein being assayed. Reportable range should not be confused with reference range. A linear range should cover 0 150 or 50 150 of the expected analyte concentration. Imaging systems such as the c600 are able to image across a much wider dynamic range and therefore linear range of detection.

When operating in the linear range no clipping occurs. Anionic blue neutral green and cationic red. The approximate linear range of each analyte is generally specified by the manufacturer or in the literature but should be confirmed by each laboratory. While a linear range for the lc ms instruments is usually fairly narrow and depends on the compound several possibilities.

If an amplifier were perfectly linear no distortion harmonic distortion or. Output input gain. Within the linear range of the assay 5 25 mcg ml the more protein present the more coomassie binds. The bradford protein assay 1 is one of several simple methods commonly used to determine the total protein concentration of a sample.

Often a sample is so concentrated that when you assay the prescribed volume of. If curve fitting must be done manually a point to point fit will usually be more accurate than a linear fit to the entire range of standard points see figure.