Leica Biosystems PELORIS_PELORIS II - Manual (Page 56)

Running Protocols
Leica PELORIS™ User Manual Rev K © Leica Biosystems Melbourne Pty Ltd 2011 56
3.6 Retort Scheduling
The Peloris tissue processor allows you to simultaneously run protocols in both retorts. The
automatic scheduling function attempts to assign reagent stations and start times so that there are
no clashes and it may alter your requested end time by starting the protocol early or by inserting a
delay time (see 3.6.1 Delayed End Times and Initial Fills).
Also, when starting a second protocol you may notice that the reagent stations assigned when a
protocol was loaded change as it begins to run. This occurs when the instrument must alter the
assignment to allow for the first protocol’s current reagent requirements.
It is sometimes not possible to schedule a second protocol. This situation and possible remedies are
discussed in 3.6.2 Unavoidable Reagent Clashes. Also, protocols will sometimes fail if a reagent
station unexpectedly becomes unavailable. 3.6.3 Unavailable Reagents describes the best ways to
avoid this situation.
3.6.1 Delayed End Times and Initial Fills
Protocols do not need to start immediately and it is possible to set a required end time that
necessitates a delay before the actual protocol begins. This delay period can extend to many days.
Also, when selecting the ASAP (As Soon As Possible) scheduling option, or if you have requested an
end time that is not achievable, the Peloris tissue processor may be forced to delay the start of the
protocol. During the protocol delay period the Peloris tissue processor will protect your cassettes by
covering them with reagent; this process is called an initial fill.
During the initial fill, the retort is filled with the first scheduled reagent (usually a fixative) to protect
the samples. Unless the reagent is wax no heating or agitation occurs. If the initial step is wax (for
reprocessing or wax only protocols), the retort temperature will be set to wax standby, and the
stirrer will be set to the first step’s speed. Once the initial fill period is over the protocol will run
normally and will finish at the predicted end time.
We recommend that all protocols start with a fixative step (even if only very short) so that a fixative
is used for any initial fill. If there is no fixative step, an initial fill may leave your tissue covered with
dehydrant for a long period and this can cause the tissue to become hard and brittle.
3.6.2 Unavoidable Reagent Clashes
Unavoidable clashes often occur when there are insufficient reagent stations available for both
protocols to satisfy the reagent selection rules (see 4.1.2 Reagent Selection Method). This occurs
more frequently when using “by type” and “by station” protocols as they have limited station
assignment flexibility.
Always ensure sufficient stations of the first reagent group or type so a station is available for an
initial fill.