Thorough characterization of new strains of mutant mice, including survey radiographs (in coordination with Imaging Services), hematology and serum chemistry, complete gross necropsy, and extensive histopathology studies (in conjunction with the Histology Laboratory). can be performed. Mutant phenotype evaluation takes into account strain background, animal disease status, and animal husbandry conditions.
Hematology & Serum Chemistry
For many mouse mutations, the lesion under investigation will be primarily biochemical rather than anatomical. This is particularly true for models of diabetes and other metabolic diseases. Thus, ante- or post-mortem determinations of hematologic and serum chemical abnormalities is needed. Hematology analysis is performed using a HemaVet 950 instrument, which measures 20 hematology parameters and performs a while blood cell differential on as little as 20 µl of blood. Serum chemistry analysis is performed using a VetScan 2 instrument. Serum samples (100 µl) are analyzed for: albumin, alkaline phosphatase, alanine aminotransferase, amylase, total bilirubin, blood urea nitrogen (BUN), calcium, phosphorus, creatinine, glucose, sodium, potassium, globulins, and A/G ratio.
Histopathology & Morphometry
Our skilled veterinary pathologist can provide investigators with accurate and thorough descriptions of the histologic lesions present on submitted slides. For studies involving large numbers of animals with lesions in the same organ, such as skin carcinogenesis studies, lesions can be classified by type and graded/scored by severity using a set of criteria agreed upon by the investigator and the core director and pathologist Dr. Manu Sebastian. Digital images of the slides can also be provided as needed, including morphometric analysis (e.g. proliferative index), using proprietary software.
For routine necropsy of mice, tissues are examined, collected, and fixed for 48 hours in 10% neutral buffered formalin, then placed in 70% ethanol for processing. Specific collection techniques such as freezing or fixation in special reagents can generally be accommodated as requested by the investigator. All sampled tissues are examined microscopically and digital images of both gross and microscopic lesions can be prepared.
Examined tissues typically include skin, mammary tissue, peripheral lymph nodes, salivary glands, preputial/clitoral glands, testes/ovaries, uterus, cervix, vagina, prostate, seminal vesicles, bulbourethral glands, bladder, urethra, spleen, liver, gall bladder, stomach, small intestine, large intestine, pancreas, mesenteric lymph nodes, diaphragm, peritoneum, kidneys, adrenals, ureters, thymus, heart, lung, trachea, esophagus, thyroids, parathyroids, cranium, nasal passages, oral cavity, tongue, eyes, brain, pituitary, spine, limbs, sternum, and brown adipose tissue.
Organ weights are measured to the nearest milligram to provide quantitative information regarding adiposity, muscle wasting, and overall organ atrophy or hypertrophy. The following are typically surveyed: whole body, liver, spleen, kidneys, adrenals, thymus, and heart.
For complete characterization of a mutant mouse, all tissues sampled are examined microscopically and digital images of both gross and microscopic lesions can be prepared. Tissues to be examined histologically are determined by consultation between the investigator and core's pathologist. Pathology staff will trim tissue for embedding and return the tissue to the investigator. It is the responsibility of the investigator to submit the samples to the Histology Laboratory, to arrange billing to the proper account, and to specify that slides be returned to the pathologist.
Preliminary and Final Reports are sent to the investigator by email. The Final Report includes a summary of all gross and histologic findings, interpretations of the findings, suggested additional studies, and pertinent references.