Training in Universal Precautions
All technicians and other personnel working with fresh or frozen human tissues must be trained in universal precautions. Principal investigators are responsible for providing the training. The Safety Department has a video and can provide instruction.
The exact requirements for samples (amount, normal and/or tumor, sterile/not sterile) must be clearly communicated. It is best if we understand what the tissue will be used for, and we will make every effort to get it to you as quickly as possible for RNA work. However, handling of specimens for diagnosis is our first priority, and the gross room can get very busy.
Types of Specimens
Depending on the types of specimen required, different procedures and requirements may apply, as described below:
After registration, the principal investigator and a staff pathologist will determine the type of tissue required. A search of the database will be made to determine the cases that are most appropriate for the study. The final selection will be made and the tissue retrieved from the freezers.
Fresh tissue requests will be placed on the board in the gross room, and when a suitable specimen is received for the research project, the contact person will be called to pick it up.
- Registration: Each user must register each project and have IRB approval for discard tissue.
- The principal investigator and a staff pathologist must have an initial discussion concerning which tissues are needed for a particular research project. Since most surgical cases (such as mastectomy specimens) have many (usually 20 to 40) blocks/slides, a pathologist must be involved so that the sections eventually cut will contain the type of tissue needed for the research project. Similar considerations apply to projects requiring normal tissue.
- The principal investigator requests the cases on the appropriate form (please prioritize appropriately and request no more than 10 to 15 cases at one time). The slides are pulled first and the pathologist selects the appropriate section. The corresponding block must then be pulled from storage. It will then be given to the core histotechnologist for sectioning by the pathology staff. Please allow reasonable time for this process, as well as the refilling of slides and blocks.
- Any special requirements such as the need for baking, special treatment of slides for in situ hybridization or immunohistochemistry must be discussed with the involved pathologist.
Special arrangements need to be made with Dr. Chu or Sofia Loera for paraffin sections to be cut for DNA and/or RNA extractions and PCR.
After registering the project, the principal investigator must discuss with a staff pathologist the methods of fixation, timing, how the sections are to be stored, and time needed to complete the study.
After registering the project, the principal investigator should discuss the project requirements with a staff pathologist. The technical aspects of defining the conditions of antibody staining and interpretation of the results may be complex, and require input from the pathologist as well as the supervisor of the immunohistochemistry laboratory.
The histology/cytology laboratory can process your animal tissue and/or tissue culture cells. These can be very useful as controls when working with human tissues. For example, we can put your tissue culture cells directly in the block of tumor tissue, so if the level of the mRNA or protein of interest is known from Northern or Western blots, there will be an internal control on every slide. Contact one of our staff pathologists for details.
Multitumor blocks with 10 to 12 breast cancer tissues on one slide can be prepared for analysis of multiple cases at once for either IHC or ISH. This can greatly save on time and effort for analysis. Discuss your needs with a pathology staff member.