Biomaterial Database

Interference by endogenous glycerol in an enzymatic assay of phosphatidylglycerol in amniotic fluid. 1988

D A Herold, and A E Reed

Department of Pathology, University of Virginia Medical Center, Charlottesville 22908.

We investigated the possibility of interference by endogenous glycerol with the enzymatic measurement of phosphatidylglycerol in amniotic fluid. Phosphatidylglycerol is an important indicator of fetal lung maturity. The concentrations of glycerol and phosphatidylglycerol in amniotic fluid were measured by using a coupled enzymatic assay with and without phospholipase D (EC 3.1.4.4). The precision of the assay was acceptable (within-run CV = 1.2%, between-run CV = 4.8%). Endogenous glycerol content was demonstrated to be approximately 10-20 times that of phosphatidylglycerol. This high proportion of endogenous glycerol in amniotic fluid would preclude the accurate enzymatic determination of amniotic fluid phosphatidylglycerol unless the glycerol is first removed. Nor can the actual phosphatidylglycerol concentration be determined by subtracting the endogenous glycerol concentration from the total glycerol, which includes that glycerol derived from phosphatidylglycerol. With a usual range of 9 +/- 7 mumol/L, the error for a given phosphatidylglycerol measurement of +/- 6.6 mumol/L (+/- 2 SD) clearly is too high for this assay to be clinically useful. There was no correlation between concentration of endogenous glycerol or apparent phosphatidylglycerol in amniotic fluid and the lecithin/sphingomyelin ratio of the sample.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D010713	Phosphatidylcholines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a CHOLINE moiety.	Choline Phosphoglycerides,Choline Glycerophospholipids,Phosphatidyl Choline,Phosphatidyl Cholines,Phosphatidylcholine,Choline, Phosphatidyl,Cholines, Phosphatidyl,Glycerophospholipids, Choline,Phosphoglycerides, Choline
D010715	Phosphatidylglycerols	A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.	Glycerol Phosphoglycerides,Monophosphatidylglycerols,Phosphatidylglycerol,Phosphatidyl Glycerol,Glycerol, Phosphatidyl,Phosphoglycerides, Glycerol
D010739	Phospholipase D	An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatidates with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. EC 3.1.4.4.	Lecithinase D,Phosphatidylcholine Phosphohydrolase
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D002855	Chromatography, Thin Layer	Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Thin-Layer,Thin Layer Chromatography,Chromatographies, Thin Layer,Chromatographies, Thin-Layer,Thin Layer Chromatographies,Thin-Layer Chromatographies,Thin-Layer Chromatography
D005325	Fetal Organ Maturity	Functional competence of specific organs or body systems of the FETUS in utero.	Fetal Maturity, Functional,Functional Fetal Maturity,Maturity, Fetal Organ,Maturity, Functional Fetal,Organ Maturity, Fetal
D005990	Glycerol	A trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. It is used as a solvent, emollient, pharmaceutical agent, or sweetening agent.	1,2,3-Propanetriol,Glycerin,1,2,3-Trihydroxypropane,Glycerine
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000653	Amniotic Fluid	A clear, yellowish liquid that envelopes the FETUS inside the sac of AMNION. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (AMNIOCENTESIS).	Amniotic Fluid Index,Amniotic Fluid Indices,Amniotic Fluids,Fluid Index, Amniotic,Fluid Indices, Amniotic,Fluid, Amniotic,Fluids, Amniotic,Index, Amniotic Fluid,Indices, Amniotic Fluid