H. J. Clitheroe Seton Hall College of Medicine Jersey City, New Jersey and H. W. Gerarde Esso Research and Engineering Linden, New Jersey
II
Use of the Unopette in Thin-Layer Chromatography
Thin-layer chromatography has many well known advantages over paper chromatography. However, it suffersfrom being extremely fragile. None of the commercial absorbents, with or without binders added, have overcome this fragility. With careful technique, the chromatoplates become vulnerable to damage only when the scientist is applying the substances onto the chromatoplates. Previously it has been suggested that blood-sugar, blood pipets, and the calibrated ungraduated micropipets (Lambda-Pettes), are adequate. Experience in our laboratory indicates that these types of pipets have a large enough point to disturb the surface of the absorbent material and, consequently, reduce resolution of spot separation. We have recently been using the Unopette' in our laboratories. The Unopette consists of a precision disposable self-filling and self-measuring capillary held in a plastic adaptor which fits a plastic reservoir containing the solutions of substances to be chromatographed. The uniform-bore thin-walled glass capillaries are supplied in sizes of 1, 3, 5, 10, 13, 20, 25 and 50 pl. The precision and accuracy of all the capillaries used in the Unopette system are *29& The
plastic reservoirs come in 3-ml and 7-ml sizes. The advantage of the Unopette over the micropipets for thin-layer chromatography lies in the convenient handling of the pipet itself; a spot can be placed on the chromatoplate without any disturbance of the absorbent surface thus permitting high resolution of spot separation. The figure shows the Unopette in use. Other advantages of the Unopette system lie in the convenience of reservoirs for holding standard solutions vapor-tight and in the accuracy, precision, speed, and simplicity of the method.
Unopettes are produced by Becton, Diekinson & Co., Rutherford, New Jersey.
The photograph was kindly provided by Dennir Crow of the E m Rereorsh
and Engineering Cornpony.
Volume 42, Number 1 1 , November 1965
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