Sample Retention Policies

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VDL Lab Section General Sample Retention Policy
Bacteriology Submitted samples are retained for approximately two weeks from the date they are received. Significant isolates are stored for 12 months.
Electron Microscopy

Samples submitted for negative staining will be retained for 3 days at 4 degrees Celsius, processed samples on grids will be retained for 5 weeks at room temperature.

Samples submitted for Ultrastructural diagnoses will be processed and retained in resin blocks along with corresponding semi-thin sections and thin sections for 5 years at room temperature.

Endocrinology Routine serum/plasma samples are stored (refrigerated or frozen) for at least one week after test completion before being discarded or utilized by the laboratory. Exception: As required, OFA serum samples are stored frozen for six months.
Histology Fixed, paraffin-embedded tissue samples, and the corresponding stained micro slides are retained for 5 years at room temperature.
Immunohistochemistry Fixed, paraffin-embedded tissue samples, and the corresponding stained micro slides are retained for 5 years at room temperature. Exception: Samples submitted for TSE testing and testing negative are retained for 3 years at room temperature. Samples testing positive for TSE are forwarded to the NVSL/USDA Laboratory in Ames, IA.
Udder Health All submitted samples are retained for two weeks from the date received.
Minnesota Poultry Testing Laboratory Avian serology samples are retained for 7 days after completion of testing.
Molecular Bacteriology All samples are maintained in the refrigerator for two weeks after the week of testing, and then may be discarded or utilized by the laboratory. Note: swabs may be destroyed in the extraction process.
Molecular Diagnostics Original material is kept for a minimum of two weeks. Tissue homogenate supernatants positive for PRRS, BVD and PCV2 are kept for one year.
Necropsy Fresh tissues: various specimens, selected at the discretion of the pathologist, may be retained in refrigeration for 10 days.
Fixed tissues: retained for 20 days.
Large animal remains: ordinarily will not be held after necropsy, but if requested, will be held no more than 15 days.
Companion animals and horses: see the information on handling of animal remains in our necropsy guidelines.
Parasitology Samples are retained for 7 days after submission.
Serology Serum samples are retained for 30 days after completion of testing.
Virology All tissue/serum/swab samples that have requests for virus isolation are stored for 2 years. Samples that are positive in virus isolation are stored indefinitely.

Note: If longer retention time is desired by the specimen submitter, special arrangements may be possible by contacting the laboratory.   See also  http://www.cvm.umn.edu/iar/