Operating rules
Sample reception and collection times:
Reception: Monday to Friday, 9.30 am to 1.30 pm.
Collection: Monday to Tuesday, 9.00 am to 3.00 pm. Friday, 9.00 am to 2.00 pm.
Sample submission guidelines:
• The user must submit a service request before submitting the samples; this can be done via the intranet under ‘Purchasing/Histology’. Under “Notes”, the following must be indicated: orientation of the organs, sectioning area, thickness of the sections (in micrometres), whether any preliminary sectioning is required, number of slides per sample, number of sections per slide, whether consecutive or serial sections are required, whether several different samples are to be placed on each slide, etc. Or any other specific requirements.
• For invoicing to external accounts, the user must complete the relevant request form and submit it to the service along with the samples.
• Upon handing over the samples, the user must complete the Sample Reception logbook.
• Samples must be clearly labelled, indicating the name of the principal investigator (initials) or user, and numbered with their own code. Unidentified samples will not be accepted.
Guidelines for sample collection by the user:
• Once all requested services have been completed, the Histology staff will contact the designated person to inform them to collect the slides.
• The samples will be on the table at the entrance to the Department, labelled with the order number *. Upon handing over the samples, the user must check them and complete the Sample Collection logbook.
*Frozen samples and those sectioned using the cryostat will be stored on the shelf designated for the Histology Department in the -80°C ultra-low temperature freezer number 2, located in the basement.
Booking Cryostats:
• Bookings for the Leica 1950 and 1950 DualEcoTec cryostats must be made via the Intranet (Equipment Bookings).
• In addition to staff from the Histology Department, the cryostats may be used by authorised users under the supervision of department staff or other previously authorised users. Authorised users are those whom the head of the service certifies as having sufficient experience in handling and using this equipment, and they must sign the cryostat independent user register.
• A single user and laboratory may book a maximum of 2 hours per day and a maximum of 8 hours per week. If more hours are required due to the nature of the samples, please contact the Histology Service, which may authorise additional time depending on equipment availability.
• If the reserved hours are not to be used, they must be cancelled at least 1 hour in advance. If less time is available, please notify the Histology Service.
• If there are any queries, problems or equipment malfunctions, these must be reported as soon as possible to the service manager by telephone (ext. 443865).
• Due to a fault in the cooling system of the CM1950 cryostat sample holder, this cooling system must not be switched on, and work must be carried out using only the chamber cooling system. It is recommended that this be set 2°C below the working temperature.
*Here you can download the Cryostat User Guide for Independent Users.
Preparation of paraffin blocks:
• Samples must be fixed in 4% paraformaldehyde or formaldehyde (at the investigator’s discretion), using a volume 20 times that of the sample. They should remain in the fixative overnight at 4°C, or for 1 to 2 hours at room temperature. The fixation time will depend on the origin and size of the sample.
• If it will take more than 24 hours to deliver the sample, perform several washes in 1x PBS, and store at 4°C until delivery. Exception: fat samples should be transferred directly from the fixative to 70% ethanol, and delivered as soon as possible.
• Note in the logbook how long the sample has been in the fixative or whether it is being delivered in 1x PBS or 70% ethanol. It is recommended that samples be delivered in the embedding cassette, already sectioned and cleaned. If pre-processing sectioning is requested, please specify this and the plane in which the section should be made, as well as whether decalcification is required.
Preparation of OCT blocks:
• Samples must be fixed in 4% paraformaldehyde or formaldehyde (at the investigator’s discretion), using a volume 20 times that of the sample. They should remain in the fixative overnight at 4°C, or for 1 to 2 hours at room temperature. The fixation time will depend on the origin and size of the sample.
• After fixation, the samples will be transferred to 30% sucrose (in 1x PBS), where they will remain for at least overnight. Samples may be submitted either in the fixative or in the sucrose solution.
Paraffin and frozen sections:
• Indicate the number of slides required for each sample and whether a specific number of sections is required on each slide.
• Indicate the thickness of the sections to be prepared.
• Provide the necessary boxes to hold the slides with the sections.
• For flotation sections, provide Eppendorf tubes or plates, and the antifreeze solution.
• Charges are calculated per slide, except for flotation sections, which are charged per sample.
Histological stains:
• For histological stains applied to sections taken from paraffin blocks, in addition to the stains listed on the website (Haematoxylin/Eosin, Sirius Red, Oil Red O counterstained with Haematoxylin, Nissl, Masson’s trichrome, PAS, and Perls), other stains may be performed, in which case the user must supply the specific stains required. These must be requested via the intranet using the service ‘Other paraffin stains’.
• Stains will be invoiced in sets of 5 or 10 slides (as specified in the intranet request).