Our purpose is to provide convenient histology services with the highest quality to researchers. We perform all standard histology procedures including grossing, processing, embedding, and sectioning of paraffin embedded samples. We use custom histological procedures, designed to best fit the needs of the research project.

We provide the following services:

• Processing
• Paraffin embedding
• Sectioning
• Routine H & E
• Frozen sectioning
• Sections for RNA isolation
• Sections for DNA isolation
• Select Special Stains
• Consultations for tissue preparation
• Preparation of tissue for LCM/ frozen and paraffin sectioning and staining

We accept the following specimen types:

• Human tissues
• Animal tissues
• Cell lines
• Xenografts

We offer:

• Short turnaround times
• Twice a week scheduled free pickup and delivery (call for details)

Questions we will ask:

• What solution is the tissue in now?
• What type of fixative was used, and for how long has the tissue been in fix?
• Can the tissue be cut down to a size appropriate for processing?
• Do you want to submit all the tissue or just a representative section?
• If the tumor is bisected do both pieces NEED to be in ONE cassette?
• If there are multiple tumors of the same treatment group how many do you want processed and how many blocks do you want made?
• Are your unstained slides going to be used for immuno?
• Are your unstained slides going to be used for DNA OR RNA extraction?
• If you're planning to do LCM are you aware that our H&E stainer is used to stain cases other that yours and should be considered contaminated? We can hand stain your slides

The following questions pertain to frozen sections:

• Do you want the sections fixed?
• What do you want them fixed in?
• How thick do you want the sections?
• Are there any special requirements for the tissue such as low light for fluorescence?
• Do you want to purchase a slide box to store your sections in the freezer or can you supply one to us?
• Do you want an H&E to go with the unstained sections? An H&E allows you to see the basic morphology of the tissue.

Please note that prices are subject to change and you should contact the lab to verify pricing. These prices are for JHU affiliates. All others should inquire with Helen Fedor (hfedor@jhmi.edu).

Fixation:

• Harvest the tissue and place them in their respective labeled cassettes (use ONLY pencil), place all the cassettes in a large beaker and submerge them in 10% buffered formalin for 48 hours . Cover with 2 layers of foil and place in the hood to avoid fumes or if available use plastic containers with lids.
• Pour the formalin into an "excess formalin" waste container (found in the hood) and using the same beaker, rinse the blocks in running tap water (cold is fine) for 5 minutes.
• Drain the tap water and submerge the blocks in 1x PBS and store at 4^oC until processing.

Size:

Tissues placed in the tissue cassettes should be no thicker than 3-4mm. If placing more than one piece in a cassette they should be of relatively similar size. Do not place 2 organs together in the same cassette that are different sizes - ex . Do not put mouse liver with mouse prostate lobes. If the tumor or organ is thicker than 3-4mm or proportionately larger than other pieces going into the same cassette - slice it into thinner pieces to create tissues with a similar thickness. Some space should remain between the tissue and cassette walls, i.e. it should not be stuffed full . This helps to assure the tissues are processed uniformly.

• Lymph nodes should always be placed in their own cassette unaccompanied.
• Colon and small intestines should ALWAYS be flushed out, void of any material prior to fixation and processing. This is to ensure proper fixation and sectioning of the tissue.
• Contact Bonnie if you have questions or need assistance.

Lens Paper:

Some smaller tissues need to be wrapped in lens paper to assure they will not fall out of the cassette during processing: prostate lobes and lymph nodes (if necessary). There is a special technique to folding the Lens paper -- See Bonnie for directions .

Following the initial processing of the block, request 1 H&E for each block submitted.

More cuts of each block should only be requested if the initial H&E has been reviewed and the tissue appears well fixed and suitable for the staining or further experimentation. - This helps cut costs, assures that slides and precious tissue do not get wasted and also cuts down on storage of unstained sections in the -20. Some antigens degrade over time so it is best to cut only what you need when you need it.

Do not prebake the slides -- this is to be done as the first step of IHC. This helps to preserve the antigenicity of the tissues.

Storage:

Blocks: room temperature or 4^oC -- avoid heat, direct sunlight and dust.
Unstained sections: -20^oC in a Ziploc bag or wrapped in parafilm to avoid condensation.

• Histology Work Request Form

Location: Bond St Annex, Room 305 Basement

For inquiries, please contact:
Bonnie Gambichler
Email: bgambic1@jhmi.edu
Phone 410-502-3358

Personnel:

• Senior Technician: Bonnie Gambichler, HT
• Director: Angelo De Marzo, MD PhD
• Manager: Helen Fedor, BS