Milestone s.r.l.
MM098-002
– LOGOS ONE – Operator Manual
114
9.4 Reagents
Make sure to follow the software reagents’ reuse settings (please refer to chapter 4.1.2). Check them daily to
minimize inconsistent results.
Purity of
reagents
:
1.
When the water concentration in the reagents is more than 3% volume, a progressive loss of dehydrating
effect takes place. This problem can be caused by an overshooting limit of “maximum number of cassette
to process” or “Max number of processing cycle to use” for the respective reagents.
2.
Insufficient cleaning of the rack after processing can contaminate reagents with traces of WAX.
WAX
:
1.
Can be reused several times because is left uncontaminated after every protocol.
Make sure t
o follow the software WAX’ reuse settings.
2.
Be sure to run the WAX cleaning cycle at least weekly. However if the WAX is dirty or contaminated by
reagents (alcohol smell), it must be replaced.
Milestone s.r.l. has collected some cause/effect scenarios that affect tissue quality. For further information
see TISSUE PROCESSING THROUBLESHOOTING GUIDE.
9.4.1
Alcohols quality
Introduction
The purpose of this document is to recommend procedures to overcome issues associated with
inconsistency of tissue processing brought about by water contamination of the ethanol, at a few laboratory
sites, employing SPONGE BIOPSY PADS.
Background
Feedback from laboratory sites employing a combination of tissue cassettes, with and without sponge biopsy
pads, showed that the processing artifacts are a result of water contamination of the heated ethanol step.
Sponge biopsy pad cassettes have the effect of retaining more fluid (formalin) than without sponges and
therefore easily raising the water levels in the subsequent alcohol steps.
Provided the purity of the heated ethanol is maintained
at least 99%,
the next heated step in Isopropanol
can be changed less frequently.
A secondary effect of sponge use is that retention of fluid occurs for other reagents in use and will impact on
the process time (under processing) necessitating longer times to remove fluids: in this case, the action
would be to select the next longer processing program time available, after the small biopsy program.
The quality of tissue processing results is a reflection of effective fixation and quality of reagents used, noting
that the last alcohol of the processor must be 100% (reagent grade), to avoid processing artifacts.
Conclusions:
1. Introduction of sponges into cassettes increases retention of formalin may necessitate a reduction of
reagents expiration limits.
2. Use the NEXT SIZE up processing time program, when dealing with sponges present in cassettes, to
avoid under processing.
3. If the first phase of the process in LOGOS ONE is alcohol and not formalin, introduce an extra (third)
sequential Rinsing Alcohol (100% Reagent Grade):- as a first rinse in the grossing room, for accumulating
wet tissue cassettes containing sponge biopsy pads for processing.
Reagents loaded must be 99% reagent grade.