Agar-Gel Precipitin-Inhibition Technique for Histoplasmosis Antibody Determinations

The agar-gel precipitin-inhibition technique has been modified to detect antibodies of Histoplasma capsulatum in sera from human clinical cases and experimental animals infected with this organism. By use of this modified technique, the histoplasmosis can be detected more consistently and reliably than with the direct agar-gel diffusion test, and titers are comparable to those attained by the complement-fixation serological technique.     

Agar-Gel Precipitin-Inhibition Technique for C-Reactive Protein Determinations

An application of the agargel precipitin-inhibition technique of Ray and Kadull detects the C-reactive protein present in the acute-phase human sera. The sensitivity of this procedure is compared with the capillary tube-precipitin method of Selman and Halpern.     

Agar-Gel Precipitin Technique in Anthrax Antibody Determinations

A modification of the agar-gel precipitation inhibition technique of Thorne and Belton for detecting anthrax antibodies reduces inconsistency of visually determined end points on the same sera observed by different technicians. Determination of the minimal reacting concentrations of the anthrax antigen and antibody reagents, modifications of the visualization apparatus, methods for combining reagents, and length of incubation periods contribute to the ease of the end-point determinations and the uniformity of results. When compared with the previous technique, the modified procedure is less time-consuming while retaining satisfactory reproducibility, simplicity, specificity, and sensitivity.     

Agar-Gel Precipitin-Inhibition Technique for C-Reactive Protein Determinations: II. Degree of Sensitivity and Reproducibility

The agar-gel precipitin-inhibition test (AGPI) for C-reactive protein determinations proved more sensitive than the capillary tube-precipitin procedure. Furthermore, titers of positive CRP sera were obtained by this AGPI technique. This technique was compared with other indices of infectivity, namely, the white blood cell count and the erythrocyte sedimentation rate. The ease and reproducibility of this recommended test procedure were demonstrated by technicians unfamiliar with this procedure.     

Agar-Gel Precipitin-Inhibition Technique for C-Reactive Protein Determinations: III. Quantitation of C-Reactive Protein in Serum Specimens

A quantitative C-reactive protein serological procedure has been developed. By use of this method, which is performed in agar-gel plates, from 2 to 654 μg of C-reactive protein per ml of titrated human serum can be detected. The method is based on the inhibition of a specific C-reactive protein antigen-antibody precipitate formed in agar-gel by the minimal reactive dilutions of each reagent in 48 hr. It is simple, sensitive, and readily reproducible.     

Agar-Gel Precipitin-Inhibition Test for Coccidioidomycosis: II. Serological Test Antigen Studies in Agar-Gel

In this study of saprophytic and parasitic growth-phase extracts of Coccidioides immitis, an antigen from the spherule culture supernatant fluid detected a specific antibody in heretofore serologically negative suspect coccidioidomycosis human sera when diffused in agar-gel. This antigen-antibody reaction occurred also in some of the serologically positive human coccidioidomycosis sera. This study indicates that this antigen-antibody reaction should be utilized as a possible routine serological test for complete serodiagnosis.     

Agar-Gel Precipitin-Inhibition Test for Coccidioidomycosis: I. Preliminary Evaluation of the Complement-Fixation and Agar-Gel Precipitin Tests in the Serodiagnosis of Human Coccidioidomycosis

The agar-gel precipitin-inhibition serological test for coccidioidomycosis was a more sensitive indicator of Coccidioides immitis antibodies than the tube precipitin, the agar-gel immunodiffusion, in the complement-fixation tests in assaying monkey sera, whether these sera were from prechallenge-vaccinated or postchallenged animals. When applying this technique to the assay of human sera, an analogous finding generally persisted. However, some human sera were positive by the complement-fixation test and negative by the agar-gel precipitin-inhibition test. These sera were diffused in agar-gel against various coccidioidin complement-fixation, tube precipitin, and agar-gel precipitin-inhibition test antigens with essentially negative results.     

Paper-Strip Blood-Sampling Technique for the Detection of Antibody to the Plague Organism Yersinia pestis

The paper-strip blood-sampling technique was evaluated for efficacy in plague passive hemagglutination tests. It is valuable for widespread serological surveys.     

Arbovirus Identification by an Agar-Gel Diffusion Technique

A double diffusion-in-agar test was used to investigate precipitation reactions of 75 arboviruses. Specific reactions were regularly observed with members of arbovirus groups B, California, Simbu, Turlock, Hart Park, vesicular stomatitis, and several other arboviruses as well as with a member of the Tacaribe group and a herpesvirus. The results demonstrated the feasibility of applying this technique to the identification of arboviruses.     

A Novel Technique for Viable Cell Determinations

We have developed a simple method to determine cell viability using two fluorescent dyes, Hoechst 33258 and acridine orange. When these dyes are used in combination, dead cells fluoresce brilliant blue and live cells fluoresce green. This method works over a range of dye concentrations (Hoechst 33258, 0.25-2 μg/ml; acridine orange, 1-5.0 μg/ml) and the fluorescence spectra of the two dyes are such that only one set of filters is required to visualize the effects of both dyes simultaneously. It is insensitive to a wide range of exogenous serum concentrations and is read with greater uniformity by different observers.     

Technique for Viral Neutralization Antibody Surveys in Primary Microcultures

A simplified, microplate tissue culture procedure is described which facilitates neutralization antibody surveys on large numbers of sera. A comparison of the micromethod with that employing standard tube cultures indicates it to be as sensitive and far more economical.     

Evaluation of Agar-Gel Double Diffusion for the Diagnosis of Adenovirus Infection

A medium is described which can be used to detect starch hydrolysis, gelatinase production, and denitrification by pseudomonads.     

胞内抗体技术及医学应用

胞内抗体技术是近年来随抗体工程技术发展起来的一项新型基因治疗方法．它将单链抗体表达于非淋巴细胞内,并使之定向分布于细胞核、细胞浆或内质网等部位,特异性阻断、干扰分布于该部位的大分子物质生物活性或加工分泌过程．实验证明该技术能抑制生长因子受体的表达,灭活原癌基因蛋白,抑制病毒复制．在生物科学及医学研究中具有很大应用潜力．     

Indirect Fluorescent-Antibody and Quantitative Agar-Gel Immunodiffusion Tests for the Serological Diagnosis of Paracoccidioidomycosis

The value of various serological tests in the diagnosis of paracoccidioidomycosis was studied. Quantitative agar-gel immunodiffusion and indirect immunofluorescent tests were performed, and the results were compared with those of complement fixation and qualitative agar-gel procedures. The quantitative immunodiffusion procedure was found to serve as the simplest and safest quantitative test that could be performed for evaluation purposes, whereas the indirect fluorescent-antibody test gave nonspecific reactions and, as such, proved unsuitable.     

Agar Block Technique for Identification of Mycoplasmas by Use of Fluorescent Antibody

A procedure for staining mycoplasmata colonies directly on agar blocks for examination by fluorescent microscopy is described. Areas of the agar surface appropriate for staining were demarcated by use of Lucite cylinders. Direct fluorescent-antibody staining was superior to indirect staining. The technique was very useful for determining whether cultures were mixed and for identification of mycoplasmas in either pure or mixed cultures.