Evaluation of sieving polymers for fast, reproducible electrophoretic analysis of short tandem repeats (STR) in capillaries

Efficient capillary electrophoretic STR analysis requires rapid, reproducible and robust separation of DNA fragments with reasonable capillary longevity--this is currently accomplished using proprietary commercial polymeric sieving matrices specifically developed for this separation. These matrices, while effective, are costly and do not provide adequate resolution of STR DNA fragments in capillaries with shorter effective separation lengths, increasing the time required to accomplish the separation and minimizing the potential extrapolation to other miniaturized platforms. As the forensic community looks toward next generation microchip technology as a means of processing casework more rapidly, new sieving polymers need to be evaluated for utilization in this platform. The research presented here describes the assessment of commercially-available polymeric sieving matrices for STR analysis, with consideration given to feasibility of incorporation into a microdevice. Polymer composition, molecular weight, and concentration were evaluated, along with an assessment of the effects of buffer composition, separation temperature, and capillary length. These variables were evaluated individually or collectively on the ability to resolve STR DNA fragments and the reproducibility of the separations and the results compared to a proprietary commercial product. A 600,000 Da MW poly(ethylene oxide) (PEO) solution at a 3% (w/v) concentration was determined to be the most suitable matrix for these separations. This polymer, in coated capillaries, provided highly robust and reproducible separations, with near baseline resolution of fragments having single base differences. Reductions in the temperature of the separation, from 60 degrees C to 40 degrees C, and the urea concentration of the buffer, from 7 M to 3.5 M, provided increased longevity of the PEO polymer for repeated separations. Comparison of this polymer with currently specified commercial products used for STR analysis showed that the optimized PEO matrix provided superior separations under all conditions tested. In addition, PEO could be utilized in shorter capillary systems, with a concurrent decrease in analysis time, highlighting its potential for use in shortened capillary or microdevice systems.     

The impact of genetic enhancement on equality

There apparently is a genuine possibility that genetic and non-genetic mechanisms eventually will be able to significantly enhance human capabilities and traits generally. Examining this prospect from the standpoint of equality considerations is one useful way to inquire into the effects of such enhancement technologies. Because of the nature and limitations of competing ideas of equality, we are inevitably led to investigate a very broad range of issues. This Article considers matters of distribution and withholding of scarce enhancement resources and links different versions of equality to different modes of distribution. It briefly addresses the difficulties of defining "enhancement" and "trait" and links the idea of a "merit attribute" to that of a "resource attractor." The role of disorder-based justifications is related to equality considerations, as is the possibility of the reduction or "objectification" of persons arising from the use of enhancement resources. Risks of intensified and more entrenched forms of social stratification are outlined. The Article also considers whether the notion of merit can survive, and whether the stability of democratic institutions based on a one-person, one-vote standard is threatened by attitude shifts given the new technological prospects. It refers to John Stuart Mill's "plural voting" proposal to illustrate one challenge to equal-vote democracy.     

Self-esteem and delinquency

Cross-lagged panel correlation technique is used to examine whether self-esteem has a greater effect on delinquency than delinquency has on self-esteem. Analysis of a nationwide study of tenth-grade boys shows that self-esteem is the more powerful causal factor, even when initial levels of delinquency are held constant. This result, however, is found to be stronger in the lower class than in the upper class. These data are interpreted as lending greater support to Kaplan's theory of the self-enhancing nature of delinquent behavior than to the idea of reflected appraisals.The research reported in this article was funded by a grant from the National Institute of Mental Health (MH27747), which is gratefully acknowledged. The data and tabulations utilized in this article were made available (in part) by the Institute for Social Research Social Science Archive. The data were originally collected by Dr. Jerald G. Bachman, Survey Research Center, Institute for Social Research, The University of Michigan. Neither the original collector of the data nor the archive bears any responsibility for the analyses or interpretations presented here.This article is a revised version of a paper presented at the annual meeting of the Eastern Sociological Society, Philadelphia, April 2, 1978.Received her Ph.D. from the University of Maryland and is interested particularly in the social influence on the self-concept.Received his Ph.D. from Columbia University and is interested in the structure and development of the self-concept.Received her Ph.D. from Stanford University. Current research interests are related to a longitudinal study of personality development.