PRESTO PRO is an innovative benchtop processor/stainer for high quality frozen sections. It introduces a standardized approach to processing slides using FineFIX, a patented Milestone solution, followed by fully automated staining protocols.
It is now possible to produce frozen sections with permanent-like quality by combining the artifact-free tissue freezing of PrestoCHILL with the outstanding features of the all-new PRESTO PRO processing/staining unit.
Pathologists rely heavily on the frozen section technique to provide intraoperative consultations when the surgeon requires a rapid diagnosis or immediate feedback relating to surgical margins. Frozen sections provide a short turnaround time (15-20 minutes) but with the disadvantage of lower diagnostic quality than paraffin sections due to cryoembedding artifacts and variability of staining protocols. A major reason for the lower quality versus a FFPE section is that frozen sections are only stained while FFPE sections are first processed (fixation + dehydration + clearing) and subsequently stained. Quick samples’ freezing and enhanced slide processing staining are necessary for quality diagnosis on intraoperative Frozen Sections.
The freezing is needed to have the surgical sample hard enough to be cut in a thin section mounted on a microscope slide and examined under the microscope. It is the freezing that makes the procedure fast enough to be done during a surgery. It is known that frozen section gives poor results because during the freezing the water inside the tissue creates ice crystals that enlarge and deform the cellular structure and the morphology of the tissue. The report given by the Pathologist is usually limited to a “benign” or “malignant” diagnosis when communicated to the surgeon operating. When operating on a previously confirmed malignancy, the main purpose of the pathologist is to inform the surgeon if the surgical margin is clear of residual cancer, or if residual cancer is present at the surgical margin. PrestoCHILL addresses the primary limitation of the frozen section for accurate diagnosis. Ice artifact. The maximum crystals formation phase of water is between 0 and -5°C. With conventional freezing techniques, samples stay in this range of temperature for a long time, allowing the formation of ice crystals. Cryostat freezing is obtained by cooling through air, which is not the best heat exchange medium, liquid nitrogen creates a layer of gas around the sample that insulates it from the cold liquid and slows down the freezing. Also using another type of liquid, such as Isopentane, the sample is surrounded by the medium and it is the last part of the block that freezes. All of these techniques increase the frequency and size of ice crystals that impact the final morphology. The PrestoCHILL is an advanced pre-analytical system for producing frozen section blocks in a fast, reliable and standardized way. This system allows the production of high quality frozen tissue blocks thanks to the face down cryoembedding technique and the temperature of -40°C, the best compromise between the fast freezing and the optimal temperature for cutting. The face down Cryoembedding technique permits the direct contact of the sample with the cold metal giving the fastest freezing possible and allows the user to embed tissues for frozen sections with a level of control and predictability that can surpass even paraffin embedding. The temperature of-40°C impedes the water to freeze slowly and, at the same time, gives blocks that can easily reach the optimal cutting temperature of -20°C. With PrestoCHILL, tissues freeze significantly faster than with conventional methods and the freezing time is controlled. Moreover up to 6 blocks can be prepared rapidly. The blocks are prepared with the entire tissue face in a precisely flat plane, requiring minimal trimming and resulting in little tissue wastage. Another important feature of this method is the precision: since tissue adheres to the freezing temperature metal, it can be oriented in the preferred position either flat or on edge. PrestoCHILL is a complete system with all the tools needed to achieve the best freezing and the best orientation of the tissue. The lab analysis, which comes next, will determine if additional surgery is required to remove these cancer margins. The surgeon then cuts the tissue into sections, color codes them with dyes and draws a map of the surgical site. In the lab, a technician freezes the submitted tissue, after placing relaxing cuts the specimen is placed on the flat surface of the PrestoCHILL with the lower surgical margins face down. The peripheral margins are flattened on the surface. Gentle pressure is applied to the center of the sample to insure that the deep and peripheral margins are in contact with the frozen surface. When using the Mohs kit a ring mold is then placed around the specimen and the MCC (Milestone Cryoembedding Compound) medium is applied before setting the chuck on top of mold followed by the heat extractor. After one minute the specimen is removed from the mold and transferred to the cryostat where sections are taken. The technician cuts very thin horizontal slices. The slices are placed on microscope slides, stained and covered. This meticulous process takes time. Use of PrestoCHILL allows you to rapidly prepare blocks with great precision. Using a microscope, the surgeon examines all the edges and underside of the tissue on the slides and, if any cancer cells remain, marks their location on the map. The physician then lets you know whether you need another layer of tissue removed. Back in the operating room, the surgeon injects more anesthesia if needed and removes another layer of skin, precisely where the cancer cells remain, based on the map. This entire process is repeated as many times as needed until there are no more cancer cells. PrestoCHILL utilizes a facedown cryoembedding technique that allows for accurate identification of the surgical margins. This can eliminate tedious and time consuming manipulations allowing the frozen section technician to prepare the final slides more quickly. MCC is used to embed the samples and adhere them to the cryostat chuck for sectioning. MCC has been specially formulated with a lower viscosity that flows easily into the cryomolds and enhances adhesion to the chuck. The inherent limitations of frozen sections can be corrected, overcome or eliminated with the use of Milestone PrestoCHILL and support products. These limitations may include: Time: Frozen sections need to be prepared and diagnosed quickly. The PrestoCHILL allows for rapid freezing. The ease of use, ability to handle multiple samples simultaneously and the flat plane that eliminates excessive facing time all allow the technician to produce a slide quickly. Drying artifacts. A great deal of artifact in frozen sections is a result of “drying artifact”. Slides immediately fixed for 15-60 seconds in FineFIX utilizing the FineFIX Module will show nuclear detail that rivals a formalin fixed paraffin embedded section. PrestoCHILL allows optimized sectioning of the tissue of interest as well as fatty margins to be sectioned. Best operating practices are available as video tutorials for further instruction. The quality of the section is inferior. In the hands of a well trained and experienced technician a frozen section can be cut and stained with the quality of a permanent section. This requires optimized orientation, optimized freezing temperatures and fixation of the slides immediately upon acquiring the section. Milestone PrestoCHILL and FineFIX module can optimize and standardize freezing temperature and time parameters to achieve consistent results. The use of the Milestone FineFIX module or PRESTO PRO in conjunction with FineFIX before staining will enhance the nuclear detail and eliminate air drying artifacts. PRESTO PRO is an innovative benchtop processor / stainer for introperative high quality frozen sections. It features a standardized approach to first processing up to 6 slides simultaneously, with heated FineFIX fixation step followed by fully automated staining protocols, xylene free, in a total of 150 seconds procedure. PRESTO PRO automates the processing and staining of prepared histology tissue specimens by diffusing dyes with a rotating slides’ transport, using a transport arm that moves a basket for 6 slides to the appropriate staining or wash vessel located on a circular platform. PRESTO PRO lowers and lifts the basket into and out of the vessels. PRESTO PRO has a built-in ventilation to prevent laboratory personnel exposure to chemicals.
PRESTO PRO slide stainer provides reproducible, consistent, high-quality intraoperative frozen section staining with an increased workload throughput as no need of cleaning cycle nor maintenance down time.
Due to its compact size it is small enough to fit in any laboratory, close by any cryostat and fast enough to deal with even the most urgent samples. PRESTO PRO easily adapts to any laboratory with flexible features including a fully protocol customization and programmable time per station.
FineFIX is an Ethanol-based based patented fixation and processing reagent. Its formulation with low-toxicity additives overcomes the drawbacks commonly associate with pure Ethanol or formalin-based fixatives, e.g. significant tissue shrinkage, vacuolization, pyknotic nuclei. The formalin free formulation reduces formalin exposure in the frozen section lab. Both PrestoCHILL and PRESTOPRO offer standardized temperature and time control. A USB port allows for downloading of event logs to document and download event logs. PrestoCHILL features a programmable defrost cycle to ensure that the unit is frost free while maintaining optimal set temperatures during working hours. The superior quality allows the pathologist to reach an accurate diagnosis. Freezing artifacts are reduced or eliminated with PrestoCHILL. The rapid drop through the critical temperature range of 0 and -5°C reduces the size and frequency of ice crystal formation. With conventional freezing techniques, samples stay in this temperature range for a longer time, allowing the formation of ice crystals that can compress strands of fibrous tissue giving the appearance of “bubbles”.
PRESTO PRO provides improved intraoperative frozen section morphology assuring high quality, consistent staining results independent from operator skill.
It Improves flow and productivity. While slides are automatically stained, the operator is free to cryoembed and cut new specimens.6 slide processing and staining time is reduced to 150 seconds.
- PRESTO PRO HIGH FLEXIBILITY, to set and modify protocols according to your specific requirements, using your laboratory own staining reagents.
- FULL DOCUMENTATION, with PRESTO PRO bar code reader enabling to track any single slide. Data, via Milestone MileWATCH, are made available to be imported in any LIS via Local Area Network connection. Moreover, through USB port both updating of software and downloading of event logs are made easy. Install and set PRESTO PRO anywhere in your lab; No need of fume hood or dedicated aspiration as it has a Built-in exhaust system, with available filters’ set.