[en] A solid-phase radioimmunoassay has been developed as a screening technique for tetanus antibodies in blood plasma. It is based on the principle of a commercial test for Hepatitis B antibody. Compared to previous screening techniques, the radioimmunoassay showed better stability with no apparent loss of sensitivity over a 2 month period. This technique has proved useful in determining tetanus immunity and in monitoring free antibody level in treated cases of clinical tetanus. (U.K.)

[en] The effect of routine methods of tissue fixation on autoradiographic negative chemography was investigated in adult rat palatal and tongue epithelia following the incorporation of ₃H thymidine in vivo. Tissues fixed in formalin or Bouin's without acetic acid demonstrated more negative chemography than those fixed in Bouin's fluid, formol-acetic-methanol or Carnoy's solutions. These findings were associated with the lowest silver grain counts per nucleus in the formalin fixed tissues, low grain counts in tissues fixed in Bouin's without acetic acid, but the addition of acetic acid to make complete Bouin's fluid gave results similar to those following fixation with Carnoy's solution. The highest silver grain counts were obtained with tissues fixed in formol-acetic-methanol. The relationship between negative chemography and the labelling indices of tissues was unclear except where the negative chemographic effects were severe. Formalin fixed tissues showed the maximum negative chemographic effects and the lowest labelling indices. Carnoy's solution appeared to be the fixative of choice for cell kinetic studies of oral epithelium. (author)

[en] Improvements have been developed in the radioimmunoassays (RIAs) for the naturally occurring steroids oestriol, cortisol and testosterone and for the synthetic progestagen, norethisterone. Throughputs for these assays have been increased by up to four-fold compared to conventional assay procedures. Except for oestriol, running costs were also considerably lower in the improved RIAs. The assays were validated by accepted criteria and shown to be acurate and precise. These improved RIAs have been shown to be most useful in providing rapid, accurate results to clinicians in time to influence patient treatment. (U.K.)

[en] The selection of monoclonal antibodies directed against hepatitis B surface antigen, and the effects of their subtype specificities, is reported with a view to future development of an assay system for hepatitis B virus infections. Radiolabelling of monoclonal antibodies and hepatitis B surface antigen was carried out with ¹²⁵I. (author)

[en] Evidence is provided that ¹¹¹In is more suitable than ⁵¹Cr as a label for endothelial cells and fibroblasts used as target cells in cytotoxic assays. (author)

[en] The successful application of three murine monoclonal antibodies in a solid-phase radiometricassay for ¹²⁵I labelled hepatitis B surface antigen is described. The assay compares favourably with comparable systems employing conventional heterologous anti-sera. (author)

[en] An immunoradiometric assay system for HBsAg has been developed utilising an antibody coated tube in which all the intermediate washing and reagent dispensing operations are performed automatically in a purpose built machine. The system has been evaluated by two blood transfusion service laboratories and appears to overcome the potentially high operator associated false positive rate often seen in tube assays of this type. The sensitivity of the system was found to compare favourably with the other assays in use in those laboratories. (author)

[en] The development, preparation and performance in-house of a radioimmunoassay kit for detection of hepatitis B surface antigen is described. The method is inexpensive and has a sensitivity at least equal to that of commercial preparations. Radiolabelling was carried out with ¹²⁵I. (author)

[en] Radio-labelled (I¹³¹ and In¹¹¹) antibodies have recently been studied intensely for their in vivo localizing ability. Reports indicate that many different tumour types can be detected and that at present results are comparable to, or marginally better than, those with other techniques. However, many new developments suggest that useful applications will soon be found in detecting a variety of tumours. This articles describes the methods that have been developed, the clinical results, and some future developments. (author)

[en] Methods for the determination of androgens in serum by radioimmunoassay usually involve solvent extraction to separate the steroid from other constituents and, after reaction with antibody, centrifugation to separate bound from free antigen. These procedures reduce the possibility of automation or method simplification. Methods were developed for the radioimmunoassay of testosterone by (i) replacing solvent extraction with other means of dissociating testosterone from sex-hormone binding globulin (SHBG), in particular by the reduction of pH, and (ii) eliminating centrifugation by selectively partitioning free antigen into toluene scintillator, and thus achieving separation of free from bound antigen. These methods correlated well with established methods employing solvent extraction and centrifugation (r = 0.96, P < 0.001). (author)