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HSL Advanced Diagnostics Specimens

See the main Tests section for general information on ordering tests, and specimen collection, packaging and transport.

Immunohistochemistry (stain and return only)

For stain and return IHC requests, we require sections cut at 3-4μm placed on positively charged IHC slides. Please provide an appropriate number of unstained sections to cover the number of requests per case plus an additional 2 sections for repeat staining that may be required.

IHC and FISH for interpretation

For all interpretative requests, we require an appropriate number of unstained sections plus an additional 2 unstained sections for repeat/reflex testing that may be required.

We recommend SuperFrost Plus, Leica Bond Plus or TOMO slides for all IHC staining. Please note that the use of X-tra® Slides from any manufacturer are not suitable for FISH testing.

Cutting of tissue sections to be referred to HSL-AD for IHC or FISH testing

All sections cut for IHC or FISH testing require special precautions for optimal performance and quality of staining procedures.

  • Sections should be cut onto the recommended slide type.
  • Section placement should not be excessively high. HSL-AD primarily uses the Leica Bond III platform for IHC staining and the staining area does not cover the entire surface area of the slide. (Please see life sized photograph of a Leica Bond PLUS slide for reference, this can be printed and laminated to use as a template in your microtomy area).
  • Sections from biopsies and small pieces of tissue should be placed in the area within the blue box.
  • Sections from resections and larger/ multiple pieces of tissue should be placed in the area covered by the red box.
  • Placement of tissue in this way is applicable for all slide types.
  • It is very important that the lesion of interest from mega blocks is placed on the test slides appropriately.
  • For tests performed on the Roche/Ventana and Agilent/Dako platforms, placement is not as critical, but it is always best practice to place test sections centrally on the slide.
  • Once cut, all sections for IHC and FISH should be left to dry naturally or in a slide rack above a gentle heat source in an upright position for 30 minutes to 1 hour. Ensure that there is no remaining water underneath the section before baking. The use of slides recommended in this user guide are selected to optimise the drying process, reduce the time required and significantly reduce the number of repeat tests we perform.
  • All sections for IHC or FISH should be placed in a temperature-controlled oven at 60°C for 1 hour or at 37°C overnight.
  • Sections should not be hot-plated using direct heat on the slide, as this may cause poor tissue adherence and unreliable IHC/FISH staining quality.
  • The use of X-tra® Slides from any manufacturer are not suitable for FISH testing.
  • If slide identification at the referring laboratory is done through printed labels, the maximum height of these labels must not exceed 22mm. If this is not possible, slides hand-written with pencil are preferable. 
  • This is critical as HSL-AD uses a range of staining platforms. IHC/CISH staining on these have been calibrated and validated for a specific slide surface area. Furthermore, labels extending down onto the slide staining area may exert a hydrophobic effect on the reagents applied.
  • For IHC or ISH requests for bacteria or viruses, it is best practice to place a ribbon of sections on each slide referred for testing. This reduces the possibility of staining artefacts interfering with slide interpretation, reduces the need for repeat staining and will reduce overall turnaround time. 

Any deviations from these instructions may lead to compromised staining quality.

Packaging and transport

All slides sent to us must be securely packaged in slide mailer boxes with lids taped down. Where possible, tape the slide boxes together to minimise movement inside the package. Blocks must be thoroughly secured in protective material before sending.

A padded envelope must be used for all specimens.

Ensure all material (forms, slides and blocks) is in the package before sealing. (Confirm that three points of identification are present). Please ensure the correct address label is on the envelope.

When we are returning slides/blocks to the requestor, all slides (slide mailer boxes) and blocks (secured in protective material) are sent out in securely padded envelope via Royal Mail or courier. As standard, all cases are returned to referring laboratories using 1st class postage through the Royal Mail. If you would like to arrange a courier, or want us to arrange one, please contact us directly.

Rejection criteria

Requesting laboratories will be notified where samples are unsuitable for testing. Changes to the request form or new tissue section may be requested and testing will commence once the issue has been corrected. The following issues will result in specimen rejection:

Request Forms

  • Illegible request (all request forms are designed as editable PDF documents; we recommend that requesting laboratories complete forms electronically).
  • Test(s) required not stated.
  • Requesting laboratory not stated.
  • Requesting laboratory/surgical slide/ block number not stated.


  • Number mismatch between slide/ block and request form.
  • Slide broken in transit.
  • Insufficient material received to complete testing.


Clinical Trials

  • Inclusive of points above, all requests for work coming through the laboratory as part of an organised clinical trial must have all information points completed and correct. All identifiable patient information must be anonymised (unless such information forms part of the trial process, e.g. date of birth). Cases with incorrect or no information will be rejected. All corrections to request forms or data should be corrected with a single line through the incorrect information, be signed and dated. Where appropriate, an explanation of the nature of the correction should be stated.