User manual LEICA PELORIS DUAL DATASHEET

[. . . ] A survey of standard histology texts published in the last twenty years reveals an average processing time of 15. 7 hours for "routine overnight processing" using xylene as a clearing agent. A survey of local and international laboratories shows that the average duration of a "routine overnight" schedule on an enclosed processor using xylene and excluding any additional fixation steps is 10. 3 hours (see Table 1 for details). Of course these laboratories do use shorter schedules for special purposes, where particular types of specimens are to be processed (eg. endoscopic biopsies), or where specimens falling within strict size limits are included. [. . . ] As far as possible specimens for assessment were kept identical in terms of size, fixation and source on both instruments for each processing run. Not every specimen in each run was evaluated. Any specimens that were not for evaluation but loaded into retorts on Peloris to provide a representative case load comparable to the VIP, consisted of pig tissue supplied by VBS. Typical specimens used in assessment of processing and their approximate dimensions are shown in Table 2. At each laboratory for each of 10 sequential working days, three processing runs were carried out. Two rapid schedules were run on Peloris using the two retorts. Retort A was used for the 6 hour schedule and Retort B for the 9 hour. Runs were carried out daily at either 45 °C or 55 °C. For each 6 and 9 hour run on Peloris a routine overnight run was completed on a VIP containing a normal diagnostic specimen load together with a set of the duplicate test specimens (200 ­ 250 cassettes). These served as our normal control group. Fresh reagents were provided for run 1 and not changed for the 10 runs on both Peloris and the respective VIP. For each Peloris run, in addition to the test specimens, cassettes containing various pig tissues were included to take the specimen number to 228, which provided an equivalent specimen load to that in the respective VIP processor (75% capacity of each retort). The processing schedules used are shown in Tables 3 and 4. Figure 1 illustrates the difference in step times between the various schedules used. Note that the total pump and drip times in the Peloris schedules are considerably shorter than those of the VIP. Austin Hospital (AH) Tissue Intestine Intestine Liver (pig) Liver Lung Lung Kidney (pig) Kidney Heart (pig) Heart Dimensions (mm) 30 x 8 x 5 20 x 15 x 5 20 x 20 x 5 30 x 25 x 5 20 x 20 x 5 20 x 15 x 5 20 x 15 x 5 15 x 15 x 5 20 x 20 x 5 20 x 15 x 5 Table 2. Typical specimens used in assessment of processing /2 Schedule Step No. 1 2 3 4 5 6 7 8 9 10 11 12 13 Reagent Formalin 70% ethanol 90% ethanol 100% ethanol 100% ethanol 100% ethanol 100% ethanol xylene xylene xylene Paraffin wax Paraffin wax Paraffin wax Total step time Total processing time Table 3. Peloris processing schedules P1 9 Hour Xylene Time (minutes) 0 5 10 15 40 50 50 35 40 50 35 50 65 505 531 (8. 9 hours) P2 6 Hour Xylene Time (minutes) 45 10 10 15 20 20 35 10 25 35 25 35 45 330 356 (5. 9 hours) Drip Time (seconds) 10 10 10 10 10 10 10 10 10 10 10 10 10 Temp º C 45 or 55 45 or 55 45 or 55 45 or 55 45 or 55 45 or 55 45 or 55 45 or 55 45 or 55 45 or 55 60 60 60 P/V Off Off Off Off Off Off Off Off Off Off Vac Vac Vac Stir Med Med Med Med Med Med Med Med Med Med Med Med Med Schedule Step No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Reagent Formalin Formalin 70% Ethanol 95% Ethanol 100% Ethanol 100% Ethanol 50/50 Eth/Xyl 100% Ethanol Xylene Xylene Wax Wax Wax Wax Total step time Total processing time V1 (RMH) 13 Hour Xylene Time (minutes) 30 30 30 45 45 75 90 75 60 90 60 60 60 0 750 810 (13. 5 hours) Temp ºC 40 40 40 40 40 40 40 40 40 40 58 58 58 58 P/V Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Schedule Reagent Formalin 70% Ethanol 90% Ethanol 100% Ethanol 100% Ethanol 50/50 Eth/Xyl 100% Ethanol Xylene Xylene Xylene Wax Wax Wax Wax V2 (AH) 13 Hour Xylene Time (minutes) 120 30 30 60 60 60 60 30 60 60 30 30 60 60 750 810 (13. 5 hours) Temp ºC 45 40 40 40 40 40 40 40 40 40 58 58 58 58 P/V Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Table 4. Tissue-Tek VIP processing schedules /3 Schedule and Processor Peloris 6 hr at 55 ºC Peloris 6 hr at 45 ºC Peloris 9 hr at 55 ºC Peloris 9 hr at 45 ºC VIP 13 hr control RMH VIP 13 hr control AH 0 200 Step Times in Minutes Fixation Figure 1. Routine overnight processing schedules 400 Clearing Infiltration 600 Pumping and drip time 800 1, 000 Dehydration After each processing run the specimens were embedded, sections cut and stained with H&E using the standard methods of each laboratory. During microtomy all blocks were assessed for ease of sectioning and other parameters (4). [. . . ] This clearly demonstrates the versatility of the two-retort design that allowed the processing of at least twice as many specimens as the VIP in a shorter time. Conclusion The results of comparative evaluations carried out during field trials clearly show that the design features of Peloris lead to reduced processing times without compromising quality. Tissues processed at both 45 °C and 55 °C produced consistent, high-quality results with evidence that the higher temperature is an advantage for both the 6 hour and 9 hour schedules. The trials were completed efficiently, causing little disruption in the participating laboratories, due in large part to the versatility of Peloris in possessing two retorts that could be used simultaneously. In the context of a busy histopathology laboratory, our results indicate that the introduction of Peloris processing would allow large specimens to be processed in six hours, leading to the completion of more runs in a working day and the reduction of turn-around times. Acknowledgements The Biosystems Division of Leica Microsystems would like to thank Mr Terry Cass and the staff of the Anatomical Pathology Department, Division of Laboratory Medicine, Austin Health, Victoria, Australia and Mr Richard Lau and the staff of the Anatomical Pathology Department, Melbourne Health Pathology, Victoria, Australia for their valuable assistance in conducting the trials described in this paper and in the preparation of this manuscript. [. . . ]