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D C Gale

Publications and source records attributed to D C Gale.

6 recordsLinked to original sources
PubMed2000

Use of synthetic cardiolipin and lecithin in the antigen used by the venereal disease research laboratory test for serodiagnosis of syphilis.

The Venereal Disease Research Laboratory (VDRL) test is a microflocculation test for syphilis that uses an antigen containing cardiolipin, lecithin, and cholesterol. For more than 50 years, the preparation of natural cardiolipin and lecithin for this test has been based on the Pangborn method which involves isolating and purifying these components from beef hearts. This process is tedious and time-consuming and results in a variable purity range. In our studies, we found that a VDRL antigen using synthetic tetramyristoyl cardiolipin and synthetic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (lecithin) was as specific in detecting syphilis as a VDRL antigen made with natural components. In 85% of the cases, we obtained an endpoint titer of 1/2 or 1 dilution more than a titer obtained with a VDRL antigen made with natural components. The use of these pure synthetic compounds, with a purity of 99%, would offer advantages in the standardization and stability of the VDRL antigen. Because this antigen is the basic ingredient in the preparation of nontreponemal reagents such as the rapid plasma reagin, toluidine red unheated serum test, and the unheated serum reagin, the use of this synthetic VDRL antigen should also increase the reactivity of these reagents.

Cardiolipins↗
PubMed1995

Capillary electrophoresis-electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry for direct analysis of cellular proteins.

The combination of capillary electrophoresis (CE) with electrospray ionization (ESI) mass spectrometry has proven to be broadly applicable to a wide range of biologically important compounds. When combined with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry, the combined method, in addition to high-resolution separations, affords high-resolution precision mass measurements for analytes separated from complex mixtures. Direct chemical analysis of single cells has received considerable attention in recent years; the single cell approach provides a major step toward answering important questions in the field of cellular biochemistry. In this work we present preliminary results which demonstrate the feasibility of using the CE-ESI-FTICR combination as a high-performance detection scheme for the analysis of cellular proteins acquired directly from small populations (i.e., 5-10) of intact living cells. The human erythrocyte was chosen as a model system owing to its availability, relatively homogeneous composition, and thorough documentation of contents by previous researchers. In this work we demonstrate the on-line acquisition of high-resolution mass spectra (average resolution > or = 45,000 fwhm) of both the alpha and the beta chains of hemoglobin acquired from the injection of 10 human erythrocytes (corresponding to 4.5 fmol of hemoglobin). Given the extremely small volume of the human erythrocyte (typically 87 fl/cell), the techniques implemented here should also be adaptable to the study of larger mammalian cell systems.

Adult↗
PubMed1995

Bio-affinity characterization mass spectrometry.

A new approach, bio-affinity characterization mass spectrometry (BACMS), aimed at providing a more rapid, sensitive and potentially more flexible alternative to techniques presently employed for the characterization of noncovalent interactions in mixtures, such as would be encountered in combinatorial chemistry, in presented. BACMS avoids some of the difficulties and potential artifacts associated with affinity chromatography since the noncovalent associations occur in solution; thus, BACMS avoids the requirement of solid support media and the development of non-interfering linker species. This paper describes the conceptual basis for the methodology and its potential use in applications which include the screening of high affinity ligands in support of new drug development. BACMS exploits new Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry technologies which, when coupled to electrospray ionization (ESI), allow the investigation of specific noncovalent complexes formed in solution. BACMS utilizes the well-known attributes of FTICR, such as the high resolution mass analysis and (MS)n (n > or = 2) capabilities; however, it is even more directly a result of recently developed techniques involving quadrupolar excitation, such as selected-ion accumulation. These tools are demonstrated and the results illustrate the extraordinary sensitivity achievable (solution concentration of 1 x 10-9 M without the use of separations prior to ESI). Thus, the new capabilities demonstrated here, in conjunction with ESI, will be useful for the investigation of very low relative concentration noncovalent association directly from solution, and promote a faster alternative for combinatorial mixture screening and analysis.

Animals↗
PubMed1994

Sheathless capillary electrophoresis-electrospray ionization mass spectrometry using 10 mu m I.D. capillaries: analyses of tryptic digests of cytochrome c.

The analyses of tryptic digest of proteins present a difficult challenge to the analytical chemist due to the wide range of molecular masses and hydrophobicities of the peptides produced. In this study, we demonstrate the separation of tryptic digests of bovine, Candida krusei and equine cytochrome c using a new electrospray ionization (ESI) interface for CE-MS that does not require additional sheath make-up fluid or mechanical assistance to aid the ESI process. The utility of this new CE-ESI-MS interface is demonstrated using a 10 microm I.D. CE capillary where the injected sample amounts are in the 30 femtomole (of protein) region. The CE electroosmotic flow rates when aminopropylamine treated capillaries are utilized are in the 10 nl/min region for a relatively conductive buffer system (0.01 M ammonium acetate-acetic acid buffer system, pH 4.4 and a 300 V/cm field strength).

Amino Acid Sequence↗