Mouse spot assay

In vivo mammalian mutation tests are not restricted to germ cell tests. The mouse spot test described below is, again, a test used first for studying radiation-induced mutation but has also been used for screening chemicals for in vivo mutagenic potential. This test has had several proponents but compared with in vivo chromosomal assays is not widely used. 

Number of Animals. For statistical reasons, about five to ten animals pCT dose group are generally used, except in the case of labor-intensive tests where a minimum of three (e.g., for the UDS test in liver cells) or four animals is reconunended. A much larger number of animals must be used in some assays (e.g., up to 50 dams treated and several hundred Fj animals examined in mouse spot tests). For ethical reasons, such assays are seldom used. Animals should be evaluated individually. 

In Vivo Gene Mutation Assays Mouse (Coat) Spot Assay Mouse Retinoblast (Eye Spot) Assay Hprt Assay... 

Eig. 5. Several endpoint detection methods were compared for the detection of immuno-polymerase chain reaction (IPCR) amplificate from a direct IPCR (Fig. 3A) of mouse-IgG. Although all IPCR/DNA-detection combinations were able to improve the detection limit of a comparable enzyme-linked immunosorbent assays (ELISA) of approximately 10 amol IgG in a 30-fL sample volume, several differences were observed in actual detection limit, and the linearity of the concentration/signal ratio dependent on the DNA quantification was applied. Best results were obtained for PCR-ELISA (see also Fig. 6) in combination with fluorescence- or chemiluminescence-generating substrates (b, c). With photometric substrates (d) or gel electrophoresis and subsequent spot densitometry (a), a 10-fold decrease in sensitivity was observed. In addition to the more sigmoid curve in gel electrophoresis, an enhanced overall error of 20% compared to 13% in PCR-ELISA was observed for two independent assays. The simple addition of a double-strand sensitive intercalation marker to the PCR-amplificate and measurement in a fluorescence spectrometer further decreased sensitivity (e) and appears therefore to be unsuited for IPCR amplificate quantification. (Figure modified according to references 37 and 65.)... 

Propachlor caused increased aberrant metaphases in mouse bone marrow cells. Propachlor did not produce evidence of mutagenicity in the Ames spot test with or without microsomal fortification. Results of an in vivo in vitro hepatocyte DNA repair assay were negative with rats administered up to 1000 mg kg ... 

The mouse (coat) spot test uses Fj animals to detect point mutations at the c locus or recombination between the c and p genes induced in melanoblasts in utero. The mouse (eye) spot test detects eye spots resulting from induction of deletions at the p locus in utero, in precursor cells of retinal pigmented epithelial cells. This assay is considered useful for specifically detecting deletions in vivo, as well as for mechanistic studies and research purposes. 

In both regions, newborn whole blood was spotted onto filter paper, Schleicher and Schuell (S S) 903. The TSH assay was performed using the DELFIA Neonatal hTSH kit, a sensitive two-site fluoroimmunometric assay using mouse monoclonal antibodies to TSH in a direct sandwich technique (3). The sensitivity was 1.4 mU/L and 2.0 mU/L whole blood for New South Wales and Alberta, respectively. The CV% for the low range of sensitivity was reported to be approximately 15% for Alberta. New South Wales reported a CV% of 15.6% for the control at 30 mU/L whole blood. Both laboratories participated in the quality control program at the Centers for Diseeise Control (6). 

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