TriContinent 8441 series, Руководство по эксплуатации и обслуживанию

Страница: 16 / 43

2 FUNCTIONAL DESCRIPTION
2.1 INTRODUCTION
The Multiwash III is a self-contained Multiwash III featuring keypad entry of a variety of wash
parameters, including the number of rows to process and the type of plate being washed (flat-
bottom, U-bottom, or V- bottom). In addition, up to 50 different Wash sequences can be
entered by the user and saved as reusable programs in nonvolatile memory. The Multiwash
III's positive-displacement dispense pump assures accurate, consistent plate washing, with 8-
port and 12-port configurations.
To maintain the Multiwash III's reliability, the instrument performs a maintenance rinse of the
soaking microstrip after eight hours of non-use.
It is important to leave the power on to the
instrument at all times for this maintenance rinse function to occur. Leaving the power
on is critical if the Wash solution is not routinely purged from the instrument after use.
This rinse operation is designed to keep Wash solution from drying and leaving clogging salt
deposits between uses.
It is the user's responsibility to connect the Rinse reservoir filled
with distilled water to the instrument. The maintenance rinse will continue after every eight
hours of non-use.
If the Multiwash III is to be turned off, it is important to purge the Wash solution
completely out of the system to prevent damage.
This can be accomplished by performing
the Rinse operation twice with distilled water.
2.2 DISPENSING
Wash solution is dispensed by an accurate, reliable, positive-displacement pump. The
dispense sequence executes as follows:
• A valve on the syringe assembly opens the port to the Wash solution reservoir and the
pump moves in the “fill” direction to draw solution into the syringe.
• When the syringe is full, the valve moves to the dispense position.
• The pump dispenses the volume of wash solution into the microplate wells called for by the
wash program in use. During the wash cycle, the valve and syringe operate under program
control to maintain adequate wash solution in the pump to dispense the required volume.
• Wash solution flows from the syringe through flexible tubing, into the dispense needles in
the manifold, and finally into the microplate wells.
• Dispense only mode - The Multiwash III will perform an initial aspiration and then the
programmed dispense volume without a final aspiration step when the number of
programmed wash cycles is set to “0”, zero.
2.3 ASPIRATION
Waste is aspirated from the microplate wells using an air pump, Waste reservoir, and aspirate
needles. The air pump maintains a vacuum in the Waste reservoir, that is connected by
flexible tubing to the aspiration needles in the manifold. As the manifold is lowered over the
microplate, liquid in the microplate wells is aspirated by the vacuum in the waste reservoir and
the liquid is emptied into the Waste reservoir. The rate of aspiration is such that only the very
tips of the aspiration needles make contact with the liquid, thereby minimizing carry-over from
row-to-row. A liquid level sensor in the Waste reservoir signals the Multiwash III when the
Waste reservoir is nearly full. When liquid has reached the level sensor, the Waste reservoir
must be emptied before the Multiwash III will begin a new wash cycle.
Multiwash III
11