Reference

New separation method for monoclonal immunoradiometric assays and its application to assays for thyrotropin and human choriogonadotropin

New separation method for monoclonal immunoradiometric assays and its application to assays for thyrotropin and human choriogonadotropin. Rattle, S. J.; Purnell, D. R.; Williams, P. I. M.; Siddle, K.; Forrest, G. C. (Serono Diagn., Woking/Surrey GU21 5JY, UK). Clin. Chem. (Winston-Salem, N. C.), 30(9), 1457-61 (English) 1984. CODEN: CLCHAU. ISSN: 0009-9147. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 9 A novel sepn. procedure for immunoradiometric assays involving monoclonal antibodies is described in which both radiolabeled and capture antibodies are used in soln., the capture antibody being labeled with fluorescein isothiocyanate (FITC) [27072-45-3]. Sepn. is achieved by incubation with anti-FITC antibodies on magnetic particles. This technique enhances reaction kinetics relative to those of assays in which a solid-phase capture antibody is used, thus allowing faster reaction times and more economic use of the monoclonal antibodies. The use of anti-FITC magnetic solid phase produces an assay having a highly specific sepn. method, minimal nonspecific binding, and high sensitivity. The method is illustrated by application to assays for thyrotropin [9002-71-5] and human choriogonadotropin [9002-61-3].

Use of immunofluorescence and viability stains in quality control

Use of immunofluorescence and viability stains in quality control. Chilver, M. J.; Harrison, J.; Webb, T. J. B. (Process Res. Dep., Allied Brew. Prod. Ltd., Burton-on-Trent/Staffordshire, Engl.). J. Am. Soc. Brew. Chem., 36(1), 13-18 (English) 1978. CODEN: JSBCD3. ISSN: 0361-0470. DOCUMENT TYPE: Journal CA Section: 16 (Fermentations) Immunofluorescence was evaluated as a rapid quality control technique for the detection of low levels of wild yeasts in culture yeast or other brewery samples. Antiserums were prepd. against antigenic groups A to F, pooled, and absorbed with culture yeast. Using the indirect staining method and fluorescein isothiocyanate or rhodamine as fluorochrome, levels as low as 10 wild yeasts/106 cells can be detected in 3 h. Combined immunofluorescence and viability staining allows the differentiation of live and dead, culture and wild yeast cells, on the same slide by alternating the light sources. The preferred method uses fluorescein isothiocyanate [27072-45-3], excited by incident blue light, for wild yeast detection, combined with methylene blue [61-73-4], viewed by transmitted light, for viability differentiation. Fluorescein diacetate [596-09-8] is a useful viability stain for yeasts although agreement between results comparing it with methylene blue and slide culture viabilities is not exact for heat-stressed cells. Some nonbrewing yeasts require heating for 2 min at 50° before consistent results are obtained with fluorescein diacetate. An examn. of the mechanism of the action of methylene blue as a viability stain has suggested that the action is one of permeability, rather than permeability followed by enzymic redn.