NanoPhotometer
®
P-Class
User Manual
Version 2.1
Page 33 / 70
7.3.7
Biuret Assay
The colorimetric Biuret assay is not recommended with the Submicroliter Cell. Please use Cuvette Applications.
The procedure is as follows:
Parameter Screen
Standards Screen
Parameter Screen
Step 1
Press 2 to select
Cuvette
folder.
Step 2
Press 2 to select
Protein
folder.
Step 3
Press 5 to select
Biuret
mode.
Step 4
The default
Wavelength
setting is 546 nm.
Step 5
Enter the number of
Standard
concentration points (1-9)
to be used in the curve using the keypad numbers or left
and right arrows.
Step 6
Units
: The user can enter a text string up to 8 characters
long. To access a list of pre-defined units press the
Menu/Options key and then use the left/right arrows
(µg/ml, µg/µl, pmol/µl, mg/ml, mmol/l, µmol/l, g/l,
mg/l, µg/l, U/l, %, ppm, ppb, conc or none). These units
can also be edited once
OK
is pressed. This screen also
allows the number of displayed
Decimal Points (DP)
to
be selected, from 0 to 2. Note that the result will always
be fixed to 5 significant figures regardless of how many
decimal points are selected (so 98768.2 will display as
98768 even with 1 decimal point selected). Press
OK
to store the chosen parameters OR
Cancel
.
Step 7
Press
Next
to enter the next screen.
Step 8
Select the
Calibration
mode, either
Standards
(measure
prepared standards),
Manual
(keypad data entry) or
New
Standards
(previous values are blanked, new
standard can be measured).
Step 9
(if
Standards
selected) Select the number of
Replicates
using the left and right arrows. This determines the
number of standards to be measured and averaged at
each standard concentration point. Can be Off (1), 2 or
3.
Step 10
Press
Next
to enter the Standards screen OR press
Cancel
to cancel selections and return to the
Protein
folder.
Standards Screen
Step 11
Enter the concentration values by using the keypad
numbers and the up and down arrows to move between
the different standard boxes. Range is 0.001 to 9,999.
C button backspaces and clears the last digit entered.
Step 12
Press
Next
to enter the Calibration screen. If there
are duplicate or non-monotonic (increasing) entries the
unit will beep and highlight the incorrect entry OR press
Back
to return to the Parameter screen.