BASIC
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Enzyme kinetic:
Called also zero order kinetics. This method calculates the evolution of a sample, in Absorbance,
against a time period defined in a certain number of intervals. BASIC computes the straight regression
line which will average the means of the points.
BASIC allows you to select the duration of analysis reading as well as the number of intervals to be
measured.
NOTE: Reading time doesn’t take in account the lag time.
slope
N x XY X x Y
N x X X
x=
−
−
∑∑
( ) ( )
( ) ( )
2 2
60
N : Total number of point of the kinetic curve (nb of segments x segment time).
ΣX : 1+2+3+...+N x (N+1) /2
ΣY : total of absorbances at points 1, 2, 3, ... N=A+A2+A3+...+AN
ΣXY : (A1 x 1)+(A2 x 2)+(A3 x 3)+...+(AN x N)
ΣX
2
: 1+4+9+...+N
2
= N(N+1)(2N+1) /6
The slope thus calculated is expressed in delta of Abs./min.
Kinetics with standards :
Called also two-point kinetics or first order kinetics. This analysis method allows performing
measurements of Concentration in Kinetics mode. That is, to calculate the absorbance variation of a
solution within the time and to multiply the differences of Absorbance by a coefficient or to compare to
a standard measured with the same measuring conditions.
Thus, global waiting time of measurement should be indicated. Then BASIC requires confirmation on
the time consumed between the two point readings.
R
ABS ABS x f x
=
−( ) t t2 actor 1 60
ABS t1: Abs of the solution at the end of the lag time.
ABS t2: Abs of the solution at the end of the measuring time.
factor: Coefficient of molecular absorption.
tm: Measuring time.
60/tm: Ratio reducing the result to one minute.
The slope thus calculated is expressed in delta of Abs./min.
Bichromatism:
This measuring mode is recommended when sample is cloudy (turbid). Reading is done using 2
wavelengths multiplied by a factor.
F
21
Smpl. Abs.Smpl .Abs
λλ
−
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