A Direct Scanning Apparatus for Reading Electrophoretic Paper Strips

Abstract

Since the publication of papers on the electrophoresis of serum proteins in filter paper strips by Cremer and Tiselius (1950), Durrum (1950), Turba and Enenkel (1950), and Flynn and de Mayo (1951), several attempts have been made to simplify the technique by the elimination of the tedious elution and subsequent estimation of the protein fractions. Grassmann, Hannig, and Knedel (1951) rendered the strip translucent with anisol ana it was then read in the special apparatus described by . This is unobtainable in Britain and the method of construction results in a graph of small dimensions which is difficult to analyse. A much simpler apparatus was devised, which, while accurate, had the disadvantage that it was not permanent, but utilized apparatus already in the laboratory without interfering with its use for the original purpose for which it was designed. In a bigger laboratory where more estimations are carried out the need was felt for a more elaborate apparatus, and the one to be described was constructed with this end in view.The apparatus consists of a wooden box 23 in. long and 19 in. wide and approximately 4 in. high. The top is made of plywood and is covered with a sheet of perspex. In these is cut a slot i in. wide and 12 in. long.One inch from the end of the slot is an oblong opening of such a shape as to take the mounting of an EEL 37 x 50 mm. barrier layer photoelectric cell. A second piece of perspex, half the size of the top, is now cut. This has only the long slot cut in it to correspond with the slot in the top of the box. A sheet of cardboard is cut to the same shape and in addition a slit 2 in. long apd 1/10 in. wide is also cut out so as to be over the position of the photoelectric cell. Two paper rulers are pasted on the edges of the cardboard, and the exposed cardboard painted black. The smaller piece of perspex is placed over the card and the two bolted to the top of the box so that the three long slots coincide. Two narrow pieces of perspex are cemented to the top 3 in. apart so as to act as guide rails to the glass strip carrier. The lamp housing consists of a perspex box containing a 25 watt 250 volt lamp with a straight slot 2 in. long and i in. wide cut in the centre with its long axis at right angles to the guide rails. This opening is filled with a piece of i-in. perspex rod cut lengthways so as to form a cylindrical lens. The opacity left by the saw can be easily removed by painting the cut surface with acetone or perspex cement. Between the lamp and the lens is mounted a 2 x 2 in. glass filter (Chance yellow OY).The lamp house is mounted over the 1/10 in. slit so that the cylindrical lens projects a beam of light through it and on to the photoelectric cell. The house should be raised sufficiently so that the bottom of the lens just touches the glass carrier strips.A single pole, single throw switch, a 20,000 ohm potentiometer and an EEL galvanometer with a logarithmic transmission scale, are mounted in convenient places on the top of the box. Under the box and parallel with the cent...

Paper Electrophoresis of Serum Proteins: Photometric Quantitation and Comparison With Free Electrophoresis 1

“…Variables which affect electrophoretic movement of protein and peptide in a paper supported buffer medium include variations in potential gradient, temperature, pH, ionic strength and nature of the buffer used, thickness of the filter paper, evaporation, time of run, and nature of the protein itself. Paper electrophoresis is well established as a research technique, having been successfully used in serum protein and lipid analysis (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), identification of the iron-binding globulin (21), study of gastric mucins (22), serum transport of thyroglobulin (23) and identification of abnormal hemoglobins (24,25). This report relates experiences with the GrassmannHannig and Durrum methods of paper electrophoresis of serum proteins and photometric measurement of the amount of dye bound by the serum protein fractions.…”

An Electrophoretic Study of Serum and Pleural Fluid Proteins in Chest Diseases

“…The investigations we report were designed to support or disprove these impressions. Method and Materials Electrophoretic analysis was carried out by the method described by Griffiths (1953), using a caprylate-barbitone buffer, pH 8.6, ionic strength 0.05. The stained strips were scanned in an apparatus designed by Griffiths (1952).…”