Specimen requirements

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All specimens should be sent to the laboratory in an appropriately labelled specimen pot that is large enough to easily accommodate the specimen. It is unsafe practice to label specimen pots in advance of a procedure.

Factors Affecting Performance

The following is a list of factors known to significantly affect the performance of examination and interpretation of results:

  • Failure to follow the specimen acceptance policy will result in a delay to specimen processing and reporting.
  • Failure to supply adequate clinical information may result in a delay to requesting of specimen investigations and reporting.
  • Failure to label requests as urgent or HSC205 will result in a delay to specimen processing and reporting.
  • Failure to fix specimens appropriately and in a timely manner will adversely affect specimen integrity and subsequent histological examination.
  • Failure to follow instructions for the specific specimen requirements will prevent necessary examinations from being performed.
  • Failure to disclose high risk status of the specimen will put staff at unnecessary risk of infection.
  • Specimens for frozen section placed in 10% neutral buffered Formalin will result in a frozen section not being performed and therefore a rapid report would not be possible.
  • Failure to contact consultant/laboratory in advance for a frozen section may result in a delay or even a scenario where it cannot be performed, due to a lack of availability of technical staff and/or Consultant staff.
  • Specimens for immunofluorescence placed in 10% neutral buffered Formalin will prevent necessary immunofluorescence examinations.

Specimen Fixation

Specimens for routine histology are required to be placed into 10% neutral buffered Formalin, which is available on request from the laboratory. Formalin is used to fix the specimen and preserve the tissue in as life-like state as possible. If there is a delay between the removal of the tissue and fixation in Formalin, this can adversely impact the specimen integrity and therefore report.

To ensure proper specimen fixation, the following guidelines should be adhered to:

  • Specimen container – should be appropriately sized and large enough to easily accommodate the specimen
  • Formalin – ensure adequate volumes of Formalin are used
    • 1:5 tissue to Formalin ratio for very large specimens
    • 1:10 tissue to Formalin ratio for small specimens where possible
  • Ensure the details on the specimen pot and request card match and are legible
  • Ensure the lid of the specimen container is securely fastened
  • Use a plastic biohazard sealable specimen bag (where possible) for the specimen pot and place the request card in the pocket

All specimens in Formalin should be stored at room temperature and not in the fridge prior to transport to the laboratory.

High Risk Specimens

All specimens from patients who are identified as (or are likely to be) in the high risk category must be clearly labelled to ensure the health and safety of all staff. The following are common hazard group 3 pathogens considered high risk (this list is not exhaustive):  HIV, AIDS, TB, Hepatitis B and Hepatitis C. Specimens from patients with Covid-19, who are immunosuppressed, drug abusers and other high risk groups are also considered high risk.

Any samples taken where the patient is suspected of having TB MUST be divided within theatre so as to provide sufficient samples for Histology (sent in formalin) and Microbiology (sent in an empty sterile container).

To ensure health and safety of staff, high risk specimens are to be fully fixed before being processed by the laboratory. The date and time that the specimen is taken should be recorded on the request card for all high risk specimens to enable the laboratory to calculate the fixation time on receipt. This information will minimise the infection risk to staff and prevent undue delay to processing.

Frozen sections and immunofluorescence investigations will not be performed on any high risk or potentially high risk specimen.

Frozen Sections

All intra-operative frozen sections should be booked with the laboratory specimen reception 0161 276 8808 to ensure the availability of the appropriate scientific and consultant staff. Every attempt will be made to provide frozen sections during the laboratory opening hours, providing appropriate clinical and technical staff are available.

Requests for frozen sections should be made 24 hours in advance, where possible. Where this is not possible, the laboratory should be contacted at the earliest opportunity when theatre staff are aware a frozen section is required. When booking a frozen section, please provide the following information;

  • Patient information
  • High risk status
  • Clinical information
  • Clinician name
  • Theatre number
  • Contact number

The specimen for frozen section should be transported to the laboratory in an appropriately labelled dry specimen container and must arrive by 4.30pm. Formalin must not be added. Specimens should be handed directly to the technical staff at histopathology specimen reception as a matter of urgency to ensure a timely report is issued.

Frozen sections will not be performed on any high risk or potentially high risk specimen.

When the specimen is ready to be sent to the laboratory, or if there is a delay in theatre, please contact specimen reception. If a frozen section is no longer required, please contact the laboratory immediately to cancel.

 

(Last reviewed March 2021)