PubMed Health⌕ Search

Biomedical subjects

G J Litt

Publications and source records attributed to G J Litt.

7 recordsLinked to original sources
PubMed1998

High-pressure-mediated dissociation of immune complexes demonstrated in model systems.

The use of pressure to disrupt immune complexes was demonstrated in two model systems: prostate-specific antigen (PSA) and anti-PSA antibody; and epiglycanin, a mucin glycoprotein, and an antibody specific to that protein. Dissociation of the anti-PSA antibody from the immobilized PSA antigen was observed when pressures of 415 MPa and 550 MPa (1 MPa approximately 144 psi) were applied at room temperature (approximately 21 degrees C). Application of pressures ranging from 140 MPa to 550 MPa resulted in dissociation of antibody from epiglycanin. In both cases, the rebinding of dissociated antibody to immobilized antigen indicated that the effect of high pressure on the binding of the immune complexes was reversible. These findings suggest that application of high hydrostatic pressure has the potential to be used to significantly improve the sensitivity and specificity of clinical assays.

Antibodies↗
PubMed1991

Catalyzed reporter deposition, a novel method of signal amplification. II. Application to membrane immunoassays.

In a previous publication (Bobrow et al., J. Immunol. Methods (1989) 279-285), we described a novel signal amplification method, catalyzed reporter deposition (CARD), and its application to microplate immunoassays. The method utilizes the analyte-dependent reporter enzyme (ADRE) to catalyze the deposition of additional reporter onto the surface of a solid-phase immunoassay system. In this paper, we describe the utilization of CARD amplification for nonradiometric membrane assays where detection is facilitated by the formation of an insoluble chromogenic product. In the examples described, deposition of reporter is accomplished in two steps: (i) a horseradish peroxidase (HRP) ADRE catalyzes the deposition of either a biotin or fluorescein labeled phenol, and (ii) incubation with either enzyme labeled streptavidin or anti-fluorescein, respectively, results in the deposition of additional enzyme. Using this method, we have improved detection limits from 8- to greater than 200-fold depending on the amplification format and the chromogen used.

Animals↗
PubMed1989

Catalyzed reporter deposition, a novel method of signal amplification. Application to immunoassays.

A novel signal amplification method, catalyzed reporter deposition (CARD), and its application to immunoassays is described. The method involves utilizing an analyte-dependent reporter enzyme (ADRE) to catalyze the deposition of additional reporter on the surface in a solid-phase immunoassay. In the examples described, deposition of reporter is facilitated by using a horseradish peroxidase (HRP) ADRE to catalyze the deposition of biotin labeled phenols. The deposited biotins are then reacted with streptavidin-labeled enzyme, thereby resulting in deposition of enzyme. Using the ADRE to catalyze the deposition of additional enzyme results in an amplification of the signal of the ADRE alone and improves the detection limit of the assay. The method is highly sensitive, simple, flexible, and easy to implement.

Animals↗