Starch block

Hb-A2 can also be quantitated by electrophoresis. The most accurate procedures are starch block electrophoresis, cellulose acetate electrophoresis, and isoelectric focusing. 

HDL, respectively. By starch block, some of the VLDL exhibit 0 2-mobility, whereas by polyacrylamide gel electrophoresis the pre-j8 band migrates in post-)8 position, a phenomenon due to the sieving effect of the supporting medium. 

Besides starch block, electrophoresis has not seen wide use in the separation of plasma lipoproteins on a preparative scale. Since the applications of electrophoresis to the study of plasma lipoproteins have been dealt with in recent reviews (H2, L3, M4), they will not be discussed here. 

Acid phosphatase of S. aureus PS 55 is eluted from the cell surface by 1.0 M KC1 at pH 8.5. Gel filtration of this material gave a 44-fold purification. The protein seems homogeneous by gel filtration, starch block electrophoresis, and analytical ultracentrifugation with the weight of approximately 58,000 (12a). 

Starch was introduced by Kunkel and Slater (K3) and used for preparative work, as the starch block can be cut up according to fractions after separation of rather large quantities of serum. The separations are very sharp, but in practice the cutting up is difficult, as in some cases the zones are numerous and narrow and are often curved or jagged. Others studied lipoproteins (Bl) and lipids (Al) with an analogous technique. 

At the close of the dialysis the plasma was centrifuged to remove small amounts of precipitate and the clear plasma resulting was subjected to starch-block preparative zone electrophoresis by the technique of Kunkel and Slater (15). At the close of the electrophoresis 1-cm. segments of the starch block were cut and transferred to sintered glass funnels, and the proteins were quantitatively eluted with five successive 2-ml. aliquots of 0.9% sodium chloride. The filtrates containing the protein fractions were then made up to a constant volume and mixed, and small aliquots were analyzed for total protein content by the method of Lowry et al. (18). 

Mandels, M., G. L. Miller, and R. W. Slater, Separation of fungal carbohydrases by starch block zone electrophoresis. Arch. Biochem. Biophys. 1961, 93, 115-121. 

Katzka and Riss extended these rat studies (K9) and found that inhibitory material was present in gastric juice of normals and patients with pernicious anemia and in human saliva, but was absent from normal human serum, hog intrinsic factor concentrate, and purified blood group substance A. Gastric juice fractionation by starch block electrophoresis yielded inhibitory material in the protein fraction remaining at the origin, which was the largest fraction in pernicious anemia gastric juice. 

Fig. 17. Electrophoretic pattern of neutralized gastric juice on starch block, pH 6.1, 30 hours, 400 volts. The figures indicate regularly occurring protein peaks. From Grasbeck (G27).

The nature of protein peaks on starch block electrophoresis and their... 

Another change in the electrophoretic pattern of gastric juice, as a result of peptic digestion, was the marked decrease in size of the protein component localized about 1 cm toward the anode from the origin. This parallels findings obtained under similar conditions vith other techniques, i.e., decrease or disappearance of component B on starch block electrophoresis (K7), of component M4 on horizontal paper electrophoresis (B13), and of the intermediate tertiary Bia binder on vertical paper electrophoresis (G23, Ul, U2). 

Using starch block electrophoresis, Grasbeck (G27) and Horowitz and Hollander (H18) found, on elution, activity in the most anodic segment of the electropherogram of the gastric juice. Similarly Jeffries et al. (J4), using starch gel electrophoresis, found pepsin in the most anodic segment of the partition. 

Slow anodic binders of Gras-beck—on starch block electrophoresis, GuUberg—on paper electrophoresis, Jeffries et al.—on starch gel electrophoresis, Okuda and Grasbeck, and Simons and Grasbeck—on agar gel electrophoresis (binder S). 

Fast anodic binders of Grasbeck on starch block electrophoresis, and Jeffries et al. on starch gel electrophoresis as well as intermediate binder of Simons and Grasbeck on agar gel electrophoresis (binder I). 

On starch block electrophoresis of gastric juice (see Section 5), Gras-beck (G26, G27) found that the two major protein peaks showed marked... 

Schnek, A. G., and Schroeder, W. A., The relation between the minor components of whole normal human adult hemoglobin as isolated by chromatography and starch block electrophoresis. J. Amer. Chem. Soc. 83, 1472-1478 (1961). 

L9. Long, M. J., Metal ion analysis by emission spectroscopy of starch block electro-phoretically separated human serum proteins. Am. J. Med. Technol. 28, 241-256 (1962). 

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