Advice for Specimen Submission

Tissue Fixation

Proper tissue fixation and processing is essential to produce high quality histological sections. Improper fixation or inadequate processing can result in tissues that are difficult to section, give unreliable data or are completely unusable. Fixation should be performed on live tissue or cells as soon as they are dissected out; failure to fix immediately will result in poor tissue morphology due to autolysis.

Important: it is NOT appropriate to freeze tissues prior to fixation as the formation of ice crystal will destroy the cellular architecture.Here is our recommended routine fixation protocol:

  1. Fix samples intended for paraffin embedding in 10% neutral buffered formalin for 24-48 hours at room temperature. Perform fixation by placing the sample in container with a flat bottom (such as a "urine cup") and containing about 10 sample volumes of fixative. Please use caution and wear proper personal protective equipment when working with formalin, work under the fume hood as much as possible and dispose of formalin contaminated materials properly by pouring used formalin in waste bottle with hazardous waste label.

  2. Rinse samples in phosphate buffered saline.

  3. Prior to processing, samples can be held at 4◦C in 50% ethanol.

Labeling of Specimen

  • Label specimen containers with appropriate information and date.

When submitting tissue cassettes:

  • Label ALL cassettes clearly

  • Label EACH cassette with unique identification number or name

  • Use correct marking pencils or markers that will not wash away during processing (Sharpie markers should NOT be used)

Discuss with us special needs or instructions prior to sample fixation