L,m,n,p,q,r : Photometric points
Rn ：Volume of the reagent, n=1 to 4
：Through cell blank
(B1,B2,B3 )/3 ：Average value of three times passing through cell blanks
Ax ：Absorbance at photometric point x
△A(m-L) ：Change in absorbance per minute between photometric points L
and M
S ：Sample volume
Rj 、Ri: a is the volumn of reagents without correction
b is the volumn of reagents with correction
Note 1: After adding reagent 2, the 5th metering point does not immediately stir. But after the reaction
disk rotates one circle around plus 2 reaction cuvettes and then pause, it need to rotate another 22
reaction cuvettes, after which will pause and then stir.
Note 2: During photometry , the reaction liquid should be more than or equal to 150μL, and less than
or equal to 450μL.
Note 3: Be sure to enter "0(zero)" when there will be no photomitric point.
Endpoint analysis method
Endpoint analysis method is reaction takes a period of time to reach
equilibrium, due to reaction balance constants are big, all substrates (tested
substance) are transformed into product, and no increase (decrease) of
reaction solution absorbance will occur, and the degree of absorbance increase
(decrease) and the concentration of tested substance is directly proportional.
This method is called “endpoint analysis method” or balance analysis method
to be more accurately, which is the ideal analysis method mode. .
The endpoint analysis method is not sensitive to small changes of conditions
(such as enzyme amount, pH, temperature, etc.) as long as this change does
not affect the balance in a certain period of time.
figure 8-1 endpoint assay reaction curve
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