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I Clements

Publications and source records attributed to I Clements.

5 recordsLinked to original sources
PubMed1995

Use of a new fluorogenic phosphatase substrate in immunohistochemical applications.

We used the phosphatase substrate 2-(5'-chloro-2'-phosphoryloxyphenyl)-6- chloro-4-[3H]-quinazolinone, with standard alkaline phosphatase-mediated immunohistochemical techniques, to visualize a number of antibodies that bind to adult zebrafish retinal tissue. This compound, known as the ELF (enzyme-labeled-fluorescence) phosphatase substrate, produces a precipitate that fluoresces at approximately 500-580 nm (bright yellow-green). We show that the precipitated product from the ELF phosphatase substrate has a number of characteristics that make it superior to fluorescein-labeled secondary reagents. The staining produced with the ELF substrate is much more photostable than that produced by fluorescein-labeled secondary reagents, thus allowing time to examine, focus, and photograph the ELF-labeled tissue under high magnification. Moreover, the ELF precipitate exhibits a Stokes shift of greater than 100 nm, a characteristic that has enabled us to overcome the problem of distinguishing signal from background in this autofluorescent tissue. In addition, we show that the ELF product's large Stokes shift makes the ELF substrate ideal for multicolor applications.

Alkaline Phosphatase↗
PubMed1986

Monoclonal antibodies for purification and assay of IL-2.

Mouse monoclonal antibodies (Mac 002 and Mac 003) raised against recombinant human Interleukin-2 (rec IL-2), were developed for use as assay and purification reagents. In the Immunoradiometric assay, (IRMA), 125I-Mac 002 is used as tracer, with sheep polyclonal anti-rec IL-2 on the solid phase. This reliably measures rec IL-2 in the range 3-1000 ng/ml. The assay measures natural IL-2 with a lower sensitivity. For some samples of IL-2, the amount detected by IRMA is greater than expected from the biological assays, presumably because there are IL-2 molecules with antigenic, but not biological activity. This is a possible source of variation in the specific activities observed in different preparations of of IL-2. In the purification reagent, Mac 003 is immobilised on sepharose CL-4B to purify recombinant IL-2 from less than 1% in an E. Coli extract, to greater than 90% purity, in a single step with greater than 80% yield.

Animals↗