Biotek ELx808, Operator'S Manual

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| Chapter 4: Instrument Qualification
Liquid Tests
Prepare Test Solutions
BioTek offers a dye solution (PN 7120779, 25 mL; or 7120782, 125 mL) that may be
used in the stock solution formulation for Liquid Tests 1 and 2, or, if you prefer,
you may use the dye solution described below. The purpose of the formulation is
to create a solution that absorbs light at ~2.000 OD full strength when dispensed at
200 µL/well in a flat-bottom microplate.
Alternatively, any solution that gives a stable color will suffice. (This includes
substrates incubated with an enzyme preparation and then stopped with an acidic
or basic solution.) Some enzyme/substrate combinations that may be used as
alternates to the described dye are shown below:
Typical Enzyme-Substrate Combinations and Stopping Solutions
Enzyme Substrate Stopping Solution
Alkaline Phosphate
o-nitrophenyl phosphate 3N sodium hydroxide
beta-Galactosidase
o-nitrophenyl -beta-D
galactopyranoside 1M sodium carbonate
Peroxidase
2,2'-Azino di-ethylbenzothiazoline-
sulfonic acid (ABTS) citrate-phosphate buffer,
pH 2.8
Peroxidase
o-phenylenediamine 0.03N sulfuric acid
Stock Solution Formulation
The stock solution for Liquid Tests 1 and 2 may be formulated using the materials
listed below (Solution A), or by diluting a dye solution available from BioTek
(Solution B).
™
Either solution should result in an absorbance of about 2.000 when
using 200 µL in a flat-bottom microwell at 405 nm. The OD value will be
proportional to the volume in the well and the amount of FD&C No. 5
dye or QC Check Solution used. You can use a larger or smaller well
volume, or add more dye or water to adjust the solution. Note that too
small a well volume may result in increased pipetting-related errors.
Solution A
Required Materials:
•
BioTek QC Check Solution No. 1 (PN 7120779, 25 mL; or 7120782, 125 mL)
•
Deionized water
BioTek Instruments, Inc.