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For children from immigrant families, opportunities to develop additive bilingualism exist, yet bilingual attainment has varied widely. Given the significance of language development opportunities in home settings, this study examines the home language use of 20 second-generation children (ages 6-8) of Mexican and Korean descent in the United States. Using a language function framework, we provide a descriptive analysis of the communicative functions performed by these children and how their proficiency level, the interlocutors, and their home settings may influence their language use. Data include English and heritage language proficiency assessments, interviews with children and their mothers, and multiple video recordings of home interactions. Findings show little variation in the kinds of language functions performed by these children who mainly used language to convey or seek factual information, unless they were involved in imaginary play. Moreover, children found creative ways to communicate different linguistic functions as needed, even among those with limited proficiency. Interestingly, the Mexican American children had a greater tendency to use more heritage language in the home than the Korean American children, who used more English. The children rarely engaged in intersentential code-switching. Implications for educators, parents, and researchers are discussed.

Microsatellite analysis is a powerful tool for the assessment of genetic instability and loss of heterozygosity in cancer cells. However, most human tumors harbor significant numbers of normal cells, which may contribute to false-negative results. Recent techniques based on fluorescently labeled primers and semiautomated capillary electrophoresis of polymerase chain reaction (PCR) products allow a reliable quantitative assessment of (PCR) products while requiring very small numbers of cells. We report a highly sensitive protocol for the semiautomated analysis of allelic imbalance based on time-release PCR and capillary electrophoresis. With this protocol, as few as 100 cells can be used to reliably assess allelic imbalance (AI) in DNA samples. Using a panel of seven microsatellite markers, we determined allelic variation in a large set of heterozygous lymphocyte DNA samples and examined the use of different statistical analysis techniques. Using these statistical approaches, we describe a calibration method to evaluate AI from microsatellite results. Using a simple formula, cutoff points at preset confidence levels are used to decide whether allelic imbalance exists in a given sample at the loci under investigation. Our method allows the reliable detection of AI with very small amounts of DNA, and is sufficiently quantitative to assess allelic ratios in nonclonal tissue specimens.