Abstract: The amount of lipid associated sialoprotein (LSP) in body fluids such as cerebrospinal fluid, peritoneal fluid, pleural fluid, bronchial washings, saliva and sputum samples, may be determined by a method which may be automated, involving the following steps to be performed on the sample: adding a mixture of a chlorinated lower alkyl alcohol; centrifuging to yield a substantially clear upper phase; recovering the upper phase and adding to it a protein precipitating agent; mixing the resulting admixture; recovering the resulting precipitate; washing the precipitate with saline solution; centrifuging to recover the precipitate; dissolving the precipitate in water; mixing; adding to the resulting mixture an hydrolysis agent; heating; and determining the amount of lipid associated sialoprotein present by determining the optical density of the sample.

Abstract: The amount of lipid associated sialoprotein (LSP) in body fluids such as cerebrospinal fluid, peritoneal fluid, pleural fluid, bronchial washings, saliva and sputum samples, may be determined by a method which may be automated, involving the following steps to be performed on the sample: adding a mixture of a chlorinated lower alkyl alcohol; centrifuging to yield a substantially clear upper phase; recovering the upper phase and adding to it a protein precipitating agent; mixing the resulting admixture; recovering the resulting precipitate; washing the precipitate with saline solution; centrifuging to recover the precipitate; dissolving the precipitate in water; mixing; adding to the resulting mixture an hydrolysis agent; heating; and determining the amount of lipid associated sialoprotein present by determining the optical density of the sample.

Abstract: The amount of lipid bound sialic acid in a blood plasma or serum sample may be determined by an improved method, which may be automated, involving the following steps to be performed simultaneously on the sample and a standard consisting of commercially available n-acetyl nueraminic acid (NANA); diluting with a buffer; mixing the diluted sample; adding a mixture of a chlorinated lower aklyl hydrocarbon and a lower alkyl alcohol; treating by mixing and centrifuging to yield a substantially clear upper phase; treating the upper phase with a color development reagent; mixing; boiling the admixture; cooling the admixture; and determining the amount of lipid bound sialic acid present in the sample by comparing the optical density of the sample to the optical density of the NANA.

Abstract: The amount of lipid bound sialic acid in a blood plasma or serum sample may be determined by an improved method which may be automated involving the following steps to be performed simultaneously on the sample and a known standard prepared from human or animal blood or tissue; diluting with distilled water; mixing; adding a mixture of a chlorinated lower aklyl alcohol; mixing, diluting with water and then treating by mixing further and centrifuging to yield a substantially clear upper phase; recovering the upper phase and adding to it a protein precipitating agent, mixing the resulting admixture; recovering the resulting precipitate, suspending the precipitate in a hydrolysis agent and determining the amount of lipid bound sialic acid present by comparing the optical density of the sample to the optical density of the standard.

Abstract: The present invention provides a method for extracting lipid bound sialic acid from a sample of blood plasma or serum and determining the amount of sialic acid present in the sample which comprises:(a) adding to the sample a mixture of a lower alkyl alcohol and a chlorinated lower alkyl hydrocarbon so as to form a resulting admixture, the volume ratio of the lower alkyl alcohol to the chlorinated lower alkyl hydrocarbon being in the range from about 70:30 to about 85:15;(b) mixing the resulting admixture for a period of time sufficient to dissolve lipid bound sialic acid present in the sample;(c) treating the admixture so as to form a recoverable, substantially clear lipid bound sialic acid-containing upper phase;(d) separately recovering from the clear upper phase so formed a predetermined volume of the upper phase; and(e) determining the amount of lipid bound sialic acid present in the predetermined volume of the upper phase and thereby the amount of sialic acid present in the sample.

Abstract: The amount of lipid bound sialic acid in a blood plasma or serum sample may be determined by a method which may be automated involving the following steps: diluting the sample with distilled water; mixing and then cooling the diluted sample; adding a mixture of a chlorinated lower alkyl hydrocarbon and a lower alkyl alcohol; mixing, diluting with water and then treating by mixing further and centrifuging to yield a substantially clear upper phase; recovering the upper phase and adding to it a mixture of a protein precipitating agent and adsorbing material, mixing the resulting admixture; recovering the resulting precipitate, suspending the precipitate in distilled water and determining the amount of lipid bound sialic acid present.

Abstract: The amount of lipid bound sialic acid in a whole blood sample may be determined by a method, which may be automated, involving the following steps: adding to the sample a lower alkyl alcohol and deionized distilled water; mixing the resulting admixture; adding to it a mixture of lower alkyl chlorinated hydrocarbon and a lower alkyl alcohol; treating by mixing and centrifuging the mixture until a recoverable, substantially clear upper phase forms; recovering the upper phase and adding to it a protein-precipitating agent, preferably in admixture with an adsorbing material; mixing the resulting admixture; recovering the resulting precipitate, suspending the precipitate in distilled water and determining the amount of lipid bound sialic acid present. The presently preferred mixture for addition to the upper phase is a mixture of 75% by weight phosphotungstic acid and 25% by weight silica gel on a dry weight basis.

Abstract: A method for determining sialic acid in blood plasma consisting essentially of the steps of precisely diluting the sample and cooling it, extracting with a mixture of chloroform and methanol, adding water to the mixture and separating the phases, adding phosphotungstic acid to the upper layer, centrifuging the resulting mixture and removing the supernatant, suspending the resulting precipitate, adding resorcinol reagent and heating, cooling the reaction mixture and adding butyl acetate-n-butanol to obtain a blue color which can be compared with standard curves to make the determination.