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Low molecular weight carboxylic acids are separated and quantitated by capillary zone electrophoresis (CZE) with an on-column conductivity detector. The addition of 0.2-0.5 mM TTAB (tetradecyltrimethylammonlum bromide) controls the electroosmotlc flow so that all carboxylate anions pass through the detector. Unlike other CZE detection methods, conductivity detection shows a direct relationship between retention time and peak area. This confers on conductivity detection, In CZE, the unique advantage that use of an Internal standard allows accurate determination of absolute concentrations In a mixture without separate calibration of response for each component.

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A new on-column conductivity detector tor use with capillary zone electrophoresis Is described. The system, constructed with Inexpensive, readily available components, can analyze nanolter samples. Peak area Is linear with concentration over

Electrophoretic separations carried out in capillary tubes offer the possibilities of rapid and automated analyses of small volumes of complex mixtures with unprecedented resolution and sensitivity. Some emerging developments of this new instrumentation are reviewed.

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The separation of protein mixtures by capillary zone electrophoresis can be plagued by wall adsorption of the protein components, causing peak broadening and distortion. A method is presented for overcoming this problem by adding ethylene glycol to the protein sample and by choosing the running buffer and protein sample to be at different pH values and molarities. This protocol appears to work for a wide class of proteins having different molecular weights and pI values. The method has been applied to the analysis of proteins in human serum. Compared to the traditional method of agarose gel electrophoresis, the present method is more rapid and offers better resolution, suggesting its potential as a clinical diagnostic of certain disease states.

Introduction.-The use of electrophoresis as a means of separating male-producing and female-producing spermatozoa in rabbits was first attempted by V. N. Shreder (sometimes spelled "Schr6der") in 1932-1949.1 She observed that the offspring of does artificially inseminated with anode-migrating spermatozoa were predominantly female, while inseminations with cathode spermatozoa produced predominantly male offspring. Shreder proposed, therefore, that anode-migrating sperm cells are X-chromosome-bearing, and cathode-migrating sperm cells are Y-chromosomebearing. Her results show successful prediction of sex, on the basis of the above hypothesis, 80 per cent of the time.In 1936, Siljander2 attempted a repetition of Shreder's work and found that while cathode-migrating sperm gave a preponderance of males, anode-migrating sperm produced a sex ratio not significantly different from that of controls. Pilz ' and Kordts,4 in 1952, also attempted to reproduce Shreder's results. Pilz failed to obtain any electrophoretic separation of sperm and therefore did not proceed with artificial insemination. Kordts, while observing very marked separations, was unable to alter the sex ratio significantly by insemination of separated sperm.The results to be reported here, while differing in some aspects from those of Shreder, lend credence and support to her work.Methods and Materials.-Ejaculates were obtained from bucks by means of an artificial vagina slightly modified from one suggested by Emmens5 and Macirone and Walton.6 Total ejaculates were diluted 1:20 with a "glycine-Ring Zd2 buffer described by Shreder (1941) and used at a pH of 7.1. This diluted sperm suspension was then introduced into a microelectrophoresis cell, and a potential was applied from a regulated power supply. The current was made high enough to permit fairly rapid electrophoretic migration but low enough to prevent convection currents. Each run was terminated at approximately 40-50 minutes. The cell used was so constructed that only one pole was accessible for the withdrawal of migratory material. By reversal of the current, this one pole could be either the anode or the cathode. One-half to seven-tenths of a milliliter was collected from the one accessible pole and used for insemination as soon as possible.Ovulation was induced by means of mechanical stimulation, hormonal injection, or by mating the doe to a vasectomized buck just prior to insemination. Insemination was performed after lightly anesthetizing the doe with sodium pentobarbital.