YSI 2900 series, Operation And Maintenance Manual

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8.2.18 Simultaneous L-Glutamate and L-Glutamine
Refer to the previous sections on L-Glutamate and L-Glutamine for theoretical and special considerations, then follow the
instructions below to set up your instrument for simultaneous determination.
A Probe B Probe
Chemistry Glutamine Glutamate
System
Buffer YSI 2357
Calibrator
Std YSI 2736 YSI 2755
Linearity
Std
YSI 2737 YSI 2756
Membrane YSI 2735 YSI 2754
Sample
Size
20
µ
L
Unit of
Conc. mmol/L
Cal Value 5.00 5.00
End Point 30 sec
Note: See Appendix B – Concentration
Unit Conversion if concentration unit
conversion is required.
Since the Glutamine Membrane (2735) utilizes a chain of
enzyme reactions and the final reaction is a “glutamate
measurement”, free glutamate in a sample will be measured at
the Glutamine Sensor. By using the information at the Glutamate
Sensor, this free glutamate is automatically subtracted in the
instrument’s software. The algorithm looks basically like this:
(“Total Glutamate” - “Free Glutamate”) = Glutamine
Total Glutamate is the combined glutamine and glutamate probe
signal. Free Glutamate is the glutamate not derived from
Glutamine reaction.
Special Considerations:
•
The ability to select sample size (10 to 50
µ
L) may help you
optimize your system, especially if very high or very low
concentrations of one or the other of these substrates is a
problem. The optimal probe current for a calibrator is about
10 nA.
•
When measuring glutamate and glutamine, the glutamate
and glutamine sensors must be located in the same module.
9. Operational Checks and Maintenance
Cleaning, Disinfecting, and Decontaminating 9.1
Proper precautionary lab practices should be followed when handling biological hazards.
Suggested cleaning and disinfecting solutions/procedures include:
• Isopropanol 70%
• Sodium hypochlorite, 5000 ppm free available chlorine (1:10 solution of household bleach)
CAUTION: Do not use cleaning solutions on ISE probes (they will be damaged).
9.1.1 Touch Panel
Clean the touch panel with glass cleaner or isopropanol. Do not use sodium hypochlorite (bleach).
9.1.2 Decontamination Procedures
Wipe the instrument case with mild soap and water, do not immerse. If necessary, isopropanol may be used.
Remove and discard all tubing. New tubing is provided in the preventive maintenance kit. Empty the waste bottle and
wash with disinfecting agent. Remove sample module, Sipper Tube, Test Tube Holders/racks and probes according to
instructions.