The present invention discloses a screening test for detecting the presence of contaminating or infectious agents causing non-A, non-B hepatitis or AIDS in a blood donor setting. A kit for the detection of contaminating agents belonging to the group of retroviruses is also disclosed. Screening blood or blood related products so as to prevent spreading of infection or contamination due to retroviruses is now made possible by the present invention.

A nucleic acid is rapidly extracted from whole blood or a peripheral blood mononuclear cell (PBMC) fraction thereof. Extraction from the PBMC fraction is accomplished by heating the fraction at or near the boiling point of water for a few minutes and recovering the extracted nucleic acid. This rapid method is particularly useful for extracting DNA for the detection of genetic diseases or infectious agents, such as HIV-I. Whole blood can likewise be heated after it is mixed with a salt solution containing a polysaccharide, such as dextran. The extracted nucleic acid is then recovered from the heated mixture. Nucleic acids extracted in this way are available for amplification using a polymerase chain reaction. Where the presence of a specific gene is to be determined for diagnostic purposes, it can be extracted as described above and subjected to suitable amplification and detection steps.

There is disclosed a method for measuring a glycosyltransferase, for measuring an activity or a concentration of the glycosyltransferase for a specific sugar, which comprises using a constitution containing a donor which is not labelled and a substance which is specifically bound only to a product.

A chemical agent is provided for significantly preventing or blocking non-specific staining or binding of an antibody specific for Terminal deoxynucleotidyl Transferase (TdT) during immunofluorescent or immunoperoxidase assay procedures. These procedures include both immunofluorescent and immunohistochemical staining of samples followed by flow cytometric and/or microscopic analysis, respectively. The invention is practiced by selective use of casein introduced into the assay procedures at an appropriate interval prior to analysis using a labelled or tagged monoclonal antibody specific to a TdT epitope. The casein utilized successfully was obtained from a large variety of sources and includes the use of a non-fat milk product.

The invention relates to methods of performing a binding assay for an analyte of interest present in a sample based upon electrochemiluminescence at an electrode of interest. Particles are employed in the method, which are then collected in a zone at which electrochemiluminescence can be induced, wherein the amount of induced electrochemilurninescence is related to the amount of analyte in the sample.