General Expectations for Submitting Samples for Histology Services

Researchers submitting specimens for paraffin processing are responsible for:

• Grossing and/or trimming tissue before submitting to the core.
  • Researchers are familiar with the region/area of interest that they are attempting to capture.
  • CoLab staff can help discuss histology techniques in an attempt to capture the region/area of interest.
  • The thickness between 0.2 and 0.5 cm (2-5 mm) is a good guide to use when trimming samples.
• Tissue fixation then transfer to 70% ethanol for paraffin processing their samples.
  • The standard fixation protocol is either 10% neutral buffered formalin or 4% paraformaldehyde for 24-36 hours.
  • The CoLab will only accept fixed samples in 70% ethanol or non-toxic buffer as our core does not handle any fixatives.
  • The volume of fixative used should be approximately 15-20x the volume of the tissue. A large volume will tend to perform fixation adequately while keeping the reagent stable.
    • NOTE: Large specimens may not process well due to the inadequate paraffin penetrating the tissue during processing.
• Submitting specimens in a secondary container such as a Ziploc bag. 
  • A secondary container helps keep the 70% ethanol in the bag in case there is any leakage during transport.
• Using a xylene and ethanol solvent resistant pen/marker or a #2 pencil for sample ID on containers, histology cassettes or slides for staining.
  • Failure to use appropriate ethanol and xylene resistant pens for labeling will result in the sample ID's coming off during paraffin processing.
  • The CoLab can generate pre-labeled cassettes using our Tissue-Tek SmartWrite cassette printer.

Researchers submitting frozen specimens are responsible for:

• Grossing and/or trimming tissue before submitting to the core.
• Researchers are familiar with the region/area of interest that they are attempting to capture.
• The team can help discuss cryosectioning techniques in an attempt to capture the region/area of interest.
• Either freezing tissue for the core to embed in OCT or submit tissue already embedded in OCT. 
• The CoLab does not have the ability to flash freeze samples.
• Schedule an appointment with CoLab staff to drop off and pick-up samples.
• Because the specimens are temperature sensitive, meeting with CoLab staff in person is required for transferring specimens.
• Please bring dry ice when dropping off or picking up specimens. The CoLab does not carry dry ice in stock.
• Discussing the tissue orientation with the CoLab team.
• Please inform the CoLab team of the tissue orientation when submitting the samples to the core. If the tissue is in OCT, the orientation of the tissue is not visible. 

Researchers submitting specimens for immunohistochemistry staining are responsible for:

• Discussing the details of the request with the core before submitting samples and reagents.
• Researchers must contact and discuss their project with CoLab staff before any work can be performed.
• The researcher must provide the antibody/antibodiees.
• The CoLab does not have any antibodies in stock for researcher use.
• The researcher can provide the antibody with the samples submitted or the CoLab can purchase the antibody for the researcher and then will bill the researcher for the same cost once the request has been completed.
• If the request requires the work-up of an antibody, also known as optimization, this may cause delays in turnaround time.
• Selecting antibody and their starting dilutions for IHC optimization.
• Antibodies optimized with the core will require researcher selection control tissue, dilutions to begin staining and review the stained slides as the researcher knows the staining they are attempting to capture.
• Researchers must then select which dilution they prefer or if further dilutions are needed.

Appointments required for sample delivery

Once an online request form is submitted in iLab, researchers can schedule an appointment with our staff to deliver samples (fresh, frozen or fixed) to our laboratory located in B. Wayne Hughes Building 8-550. Staff that have previously met with CoLab staff are welcome to drop off samples at their convenience (please email the CoLab staff that you have dropped them off to ensure nothing is lost in transition.

• Appointment scheduling for incoming and outgoing specimens
  • Researchers are required to submit their specimens in a secondary container such as a Ziploc bag or a box. This container must have their name and Service ID (generated when submitting a request in iLab) for our staff to collect.
  • For sample capable of staying at room-temperature (paraffin blocks, samples in 70% ethanol, paraffin slides only:
    • • Drop-off location 1: B. Wayne Hughes Building, floor 8, desk 08-134
      • Drop-off location 2: B. Wayne Hughes Building, floor 8, lab 08-550
      • Researchers with badge access are also welcome to schedule an in-person sample transfer. Email galen.stewart@seattlechildrens.org.
  • Temperature sensitive items such as frozen OCT samples or antibodies are not allowed in these boxes. These items must be handed off to CoLab staff directly for the core to place them in the appropriate storage conditions.