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T Porstmann

Publications and source records attributed to T Porstmann.

87 records · Page 5Linked to original sources
PubMed1979

[Purification of horseradish peroxidase conjugated IGG by affinity chromatography. Comparison of glutaraldehyde and periodate conjugation].

By affinity chromatography of the coupling mixture on Concanavalin-A-Sepharose unlabeled IgG is completely removed. HRP conjugated IgG is then separated from free HRP by gelfiltration. Glutaraldehyde conjugation yielded 20 to 68% unlabeled IgG, depending on the duration of glutaraldehyde addition, and periodate conjugation yielded 10 to 28% unlabeled IgG. By this method fractions of conjugates with 3fold spec. act. were obtained by the glutaraldehydemethod and with 1.6fold spec. act. by periodate method as compared with gelfiltration. The periodate method guarantees a 3fold higher yield of HRP-labeled IgG compares with glutaraldehyde method. Both methods produce conjugates of the same spec. act. although the denaturation of HRP is much greater at periodate conjugation. When applying of affinity chromatography and gelfiltration. Crude HRP with 7% spec. act. of purified HRP resulted in conjugates having a spec. act. of 85% of those with purified HRP.

Animals↗
PubMed1979

[Separation of human X- and Y- chromosome-bearing spermatozoa by column chromatography (author's transl)].

Separation of X- and Y-chromosome-bearing spermatozoa has been attempted using Sephadex gel filtration. Fractions rich in X-chromosome-bearing spermatozoa were eluted in dependence on length of separation distance and on speed of elution. Spermatozoa remaining at the gel showed a higher percentage of Y-bodies compared with the untreated control. Sedimentation pattern and amount of eluted cells is influenced by eluation conditions.

Cell Separation↗
PubMed1976

[Comparative studies on the detection of Y-chromatin in native and formalin-fixed tissue or organ material (author's transl)].

Frequency of detectable Y-bodies in interphase nuclei after mepacrin staining of paraffin embedded formalin-fixed tissue was compared with those of cryostat sections of the native material and organ smears with and without formalin fixing. In formalin fixed smears from males 42--70% of investigated cells showed the Y-body. Sections of formalin-fixed and paraffin embedded male organs demonstrated in 12--24% of their cells the typical fluorescence for the Y-chromatin. High significantly less fluorescent Y-like bodies were found in smears and sections of all proofed organs from women prepared in the same manner. Mepacrin staining in combination with investigation of Barr-bodies permits a fast determination of sex of both organ smears and sections, too.

Brain↗
PubMed1975

[Problem in the partial separation of X- and Y-carrying human spermatozoa].

The introduction of a fluorescent staining technique for identification of Y chromosome made possible the distinction of X- and Y-bearing human spermatozoa. Using this fluorescence analysis the isolation of Y- and X-bearing human spermatozoa were investigated employing two different methods for separation of spermatozoa. 1. The migration of human spermatozoa in cervical mucus obtained from women shortly before mid-cycle was studied, using an in-vitro method for horizontal sperm penetration. Basing on the progressive sperm motility in cervical mucus, a fraction rich in Y-bearing spermatozoa in the frontal zone of sperm migration was found. 2. Gradient centrifugation at different rotor speeds using a discontinous sucrose gradient has been employed for separation of human spermatozoa. A significant trend for separation of Y- and X-bearing spermatozoa was demonstrated. The results were shortly discussed.

Centrifugation, Density Gradient↗
PubMedDate not supplied

A sensitive non-isotopic assay specific for HIV-1 associated reverse transcriptase.

A sensitive non-isotopic assay for specific detection of reverse transcriptase (RT) of the human immunodeficiency virus type 1 (HIV-1) is described using 5-bromo-2'-deoxyuridine triphosphate (BrdUTP) instead of tritiated thymidine triphosphate. After the RT reaction the template primer is degraded by alkaline hydrolysis. Single-stranded poly.(BrdU) is detected in an immunoenzymometric assay using monoclonal anti-BrdU antibodies. The specificity of the assay is demonstrated by the isolation of RT from virus lysate by an insolubilised monoclonal anti-HIV-1 RT antibody prior to the RT reaction. Immunological RT binding leads to a tenfold increase in analytical sensitivity since substances inhibiting the RT reaction can be removed. This non-isotopic assay is some 30 times more sensitive than the classical radioisotopic RT assay. In terms of RT determination, however, there is a good correlation between these tests (r = 0.96). Several filtrations are no longer necessary to remove non-incorporated nucleotides. The test can be adapted to microtitre plates and hence is easy to automate.

Antibodies, Monoclonal↗