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The information, numerical data and notes contained in this document represent the current state of scientific knowledge and state-of-the-art technology as we understand it following thorough investigation in this field. SLEE medical GmbH is under no obligation to update the present manual periodically and on an ongoing basis according to the latest technical developments, nor to provide our customers with additional copies, updates etc.
CONTENT INTENDED USE ___________________________________________________________ 7 SYMBOLS ________________________________________________________________ 7 OVERVIEW DEVICE _______________________________________________________ 8 SAFETY NOTES ___________________________________________________________ 9 Hand wheel stop Finger protection Electrical power connection Working with knives and disposable blades COMPONENTS __________________________________________________________ 13 Standard components and optional components SPECIFICATIONS _________________________________________________________ 14 UNPACKING AND INSTALLATION _________________________________________ 16 Unpacking the device Installation site requirements...
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Fast approach to specimen Slow approach to specimen Thickness adjustment for trimming 9.10 Thickness adjustment for cut 9.11 Trimming of specimen 9.12 Manual cutting 9.13 Anti-roll plate 9.14 Tips and tricks – tissue sectioning 9.15 Tips and tricks – cutting artifacts 9.16 Tips and tricks –...
1 INTENDED USE The floor standing open top cryostat MEV / MEV + is a laboratory device and designed for rapid freezing and cutting thin sections of frozen specimens. It is intended for professional use in routine and research laboratories in the fields of biology, medicine and industry.
4 SAFETY NOTES The Slee open top cryostat MEV / MEV + is provided with the following safety features: MEV + Hand wheel stop • • Finger protection for knife- and blade-holder • • Collapsible hand wheel lever • •...
4.1 Hand wheel stop Always use the finger protection with the knife- / blade holder and put hand wheel in stop position • if you adjust the blade, the knife or the specimen, • before changing the specimen, • if the appliance is not being used (break, weekend, etc.).
4.2 Finger protection Always use the finger protection for the blade and knife holder and the hand wheel lock, • before you start any work with the knife or speci- men, • before changing the specimen, • if the appliance is not being used (break, weekend, etc.).
4.3 Electrical power connection Do not use any extension lead. Before installing the device, make sure that the electrical connection values match the specifica- tions on the type plate and that a constant power supply is guaranteed. Please note that the compressor requires a starting current of 25 to 35 A.
5 COMPONENTS 5.1 Standard components and optional components The Slee open top cryostat MEV is supplied with standard components (•) and can be equipped with optional components (o). The MEV + is a certain type of configuration. It cannot be adjusted.
6 SPECIFICATIONS All temperature specifications refer to an ambient temperature of +20 °C and a relative humidity of 60 %. General MEV + Nominal power 230 V AC 115 V AC 230 V AC 115 V AC ±10 % ±10 % ±10 % ±10 % Nominal frequency...
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Chamber defrost MEV + Automatic defrost window must be closed. Hot gas defrost, time selectable, 1 - 3 times / 24 h or manual defrost on request Automatic stop at -5 °C chamber temperature / +20 °C evaporator temperature Freezing bar MEV + Minimum temperature 10 K below chamber temperature...
7 UNPACKING AND INSTALLATION Unpacking the device On delivery, you will receive the device packed upright in a cardboard box on a wooden pallet. It is equipped with four castors and two locking feet, height adjustable at the front. When the device is delivered, check the tilt and impact indicators attached to the packaging. If the tilt indicators are active (blue arrowhead), the appliance was transported lying flat, tilted too much or fell over during transportation.
7.2 Installation site requirements The installation site for the MEV / MEV + should meet the following conditions to ensure the specified device performance: • Maximum ambient temperature of 22 °C • No direct sunlight into or onto the cooling chamber •...
7.3 Installation To open the chamber, slide the window to the top. Remove the transport security underneath the specimen holder and position the waste tray. Wait at least 4 hours before switching on the device (especially if you are not sure that the device was not tilted). Failure to comply may result in severe damage to the device.
7.4 Collapsible hand wheel lever The device is delivered with a ready to use hand wheel lever. For safety reasons, the lever of the hand wheel is folded in for transportation. Before you start any work unfold the hand wheel lever by simply pulling the lever into a horizontal position.
8 INITIAL OPERATION 8.1 Main display Time THU 13:05:05 The main display will show the day and time, the cutting thickness, the CUT: 7 µm Trim: 19µm trimming thickness, the current chamber temperature, the target cham- ber temperature, the status of the quick freeze unit (optional), the total Cha: -20 °C (-22) QF: 0 electronic status of the device and a cutting counter (optional).
8.3 LED-display OSEI-system Slee cryostats are equipped with the Slee OSEI-system as standard: Optical Status and Error Indication. LEDs of different colors in the operating chamber enable quick and easy detection of the current status of the cryostat. Possible application or system errors are promptly indicated by colored light and thus increase operating safety.
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Error messages: Error messages can be acknowledged by pressing the ESC button. UV-C light for surface disinfection, continuous [only applicable for devices equipped with this feature] • During UV-C surface disinfection, all LEDs are switched off and the UV-C lamp becomes active. UV-C light for surface disinfection.
8.4 Software settings Software settings and feed: Press MENU ENTER, to open the settings menu. > Chamber temp. -20 °C Quickfreeze UV disinfection Light Auto To move down in the main menu list, press >FAST<. Retraction 5 µm Start defrost Contrast >...
8.5 Automatic defrost, disinfection and power saving settings Software settings: Press MENU ENTER, to open the settings menu. > Chamber temp -20 °C Quickfreeze UV disinfection Light Auto Select program settings and press MENU ENTER, to TIME TUE 13:05:05 open the menu for setting automatic defrost and power Language English saving times.
Quick freeze (optional): Press MENU ENTER for 2 Sec, to start the quick freeze > TIME 13:05:05 (optional) function. After 10 min it stops automatically. Language English Display version Program settings 5 µm Settings for disinfection parameters: The disinfection cycle works in a semi-automated way. Defr.
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If AUTO is selected, the white operating light switches off automatically after the time specified under light duration and switches to the respective status indication (red or blue). Light duration 0 - 99 minutes Chamber increase The default setting for the chamber temperature increase is set to -15 °C. Energy saving mode For power saving, a higher temperature can be set for defined times and / or days.
9 OPERATION OF MICROTOME 9.1 Insertion of disposable blades Activate the handwheel lock. Fold down the finger protection. Release the blade lock by turning the right-hand lever on the blade holder anticlockwise. Remove the blade if necessary. Release the blade lock to remove the blade. Insert the new blade from the side.
9.2 Orientation of disposable blades Activate the handwheel lock. Fold down the finger protection. For adjusting the cutting angle of the blade, loosen the blade holder fixation by turning the right lever on the blade holder base counter clockwise. Tilting the blade holder towards the sample increases the cutting angle, tilting the blade holder away from the sample reduces the cutting angle.
9.3 Insertion and orientation of microtome knives Activate the handwheel lock. Loosen the blade holder by turning the fixing screws counter clockwise. Loosening the knife holder and inserting a microtome knife. Remove / insert the microtome knife. Adjust the height of the knife by turning the adjusting wheels on the right and left side of the knife holder.
9.4 Specimen mounting The device is equipped with 24 freezing positions max. (24 stand- Specimen ard resp. 21 + 2 [version incl. quick freezing positions]). The tem- perature of the quick freezing positions is approx. 10 °C lower Embedding medium than the actual cryo chamber temperature.
9.6 Specimen orientation adjustment Turn the hand wheel to its highest position and activate the hand wheel stop. For orientation of the specimen, open the fixing lever at the left side of the object holder counterclockwise (1). To adjust the orientation, turn the right-hand orientation screw (2).
9.7 Fast approach to specimen Press >FAST<, to move the knife holder base towards the sample. Press <FAST>, to move the knife holder away from the sample. 9.8 Slow approach to specimen Press >SLOW<, to move the knife holder base slowly towards the sample. 9.9 Thickness adjustment for trimming To change the trimming settings, press TRIM continuously and press + or - o increase or decrease the value.
9.12 Manual cutting Deactivate the hand wheel stop. Release the finger protection. Turn hand wheel evenly clockwise. A counter clockwise movement of the hand wheel will also result in cutting and incremental advance of the specimen. Approach specimen either by trimming or slow approach. To set the cutting thickness, press + or -, to change the setting.
9.13 Anti-roll plate Each device is equipped with an anti-roll plate. To adjust the vertical position of the anti-roll plate, turn the small wheel on the basis of the anti-roll plate to the left (to- wards blade) or to the right (away from blade). Vertical adjustment of anti-roll plate.
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It is recommended to adjust the setting of the height of the anti-roll plate during the cutting process. Manual_MEV_MEV+_2024-06-001.00_EN.docx...
9.14 Tips and tricks – tissue sectioning The temperature of the cryostat plays an important role in the quality of the tissue sections obtained. Each type of tissue requires a different temperature. The following list provides an indication. Please note that the temperature ranges indicated in the table below are approximate values and may require adjustments for individual tissues.
9.15 Tips and tricks – cutting artifacts Cutting artifact Cause Remediation Alternating thin and thick wrong temperature of the cutting edge / select temperature according to the tissue blade type cuts wrong temperature of the cryo chamber adjust temperature sample is not optimally fixed on specimen remove sample and freeze again holder Squeaking sound when...
handling too rough work more cautiously, more carefully specimen is too cold Section shows horizontal correct temperature columns warm up specimen 9.16 Tips and tricks – cutting angle Problem Cause Remediation Hard tissue does not cut cutting angle is too small tilting the blade away from the specimen well increases the clearance angle...
UV-C light without the addition of chemicals. The cryostat MEV / MEV + can be optionally equipped with an UV-C light source that can either be automatically activated (see chapter 8.5) or manually activated.
10.2 Installation instructions for UV-C lamp Please follow the respective steps and pay attention to the relevant instructions. Never touch the UV-C lamp directly on the glass, since this may reduce the durability. Picture 1 Slide the UV-C lamp as shown into the glass bulb.
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Picture 5 Once the plug is connected to the UV-C lamp, the UV-C lamp unit can finally be clipped into the retaining clips. Picture 6 Done. Picture 7 Manual_MEV_MEV+_2024-06-001.00_EN.docx...
10.3 Quick freeze position [only for devices with this optional feature] The MEV + floor-standing cryostat is equipped with a quick freeze position (2 positions) as standard. The MEV floor-standing cryostat can be optionally equipped with a quick freeze position. Upon activation, the installed element will cool the two quick freeze positions down to approximately -55 °C.
10.6 Heat extractor For an even more rapid freezing process with improved structural preservation of tissues, the device is equipped with a heat extractor. Apply the heat extractor on top of the spec- imen during the freezing process. Illustration similar The application of the heat extractor can lead to a change of orientation of the specimen in the frozen block, especially when it comes to smaller samples.
10.8 Complete defrosting of the device It is highly recommended to defrost the device at least every 6 months. If the device is used regularly in warm tropical climate, a more frequent complete defrost might be necessary. The device should be defrosted for a minimum period of 48 h, better over the weekend.
11 CLEANING AND MAINTENANCE 11.1 Cleaning The recommended frequency of cleaning of the cryostat chamber depends on how frequently the device is used. Wear protective clothing and disposable gloves according to Good Laboratory Practices. Please take note of the safety aspects of the device. Only use aqueous and alcohol-based cleaning agents, no Acetone or Xylene.
Cleaning of blade holder (see chapter 11.4). Cleaning of window. Monthly Check of temperature sensor in cryo chamber. Cleaning of cryostat ventilation (see chapter 11.5). Yearly Complete service (performed by authorized Slee service technician) • check of all functions • complete defrost •...
11.4 Cleaning of disposable blade holder Turn the handwheel to the highest position and activate the handwheel lock. Fold the pressure plate forwards using the lever. Remove the blade from the blade holder. Loosen the upper part of the blade holder by turning the right-hand lever counterclock- wise.
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Separate the lateral slide from the eccentric shaft by simultaneously turning and pulling out the shaft. To pull out the eccentric shaft, it must be ro- tated over the small pin in the carriage. To do this, push the pin into the carriage and turn the shaft over it.
11.5 Cleaning of cryostat ventilation During daily use, dust settles on the fins of the condenser. This can affect the cooling capacity of the appliance. Monthly cleaning of the cryostat ventilation is recommended. Picture MEV (cleaning from the side) MEV: 1 side ventilation grille MEV +: 2 ventilation grilles at the front We recommend to use a vacuum cleaner for cleaning.
13 Service Internal components should only be serviced by technicians authorized by SLEE medical GmbH. If technical service or spare parts are necessary, please contact your local SLEE medical GmbH distributor. Please have the following information available: • complete contact details, •...
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