Abstract:
A pipette nozzle is provided for use on a movable arm on an automated pipette machine. The pipette nozzle includes a body defining a passage therethrough and having at least two seating surfaces provided on the body. The first seating surface is configured to receive and sealingly mate with a first size of pipette tip in a manner such that the first end of the passage is in fluid communication with the first size of pipette tip. The second seating surface is configured to correspondingly receive, sealingly mate and provide passage first end fluid communication with a second size of pipette tip. There is also provided an automated pipette machine which includes a tip ejector system including an arm that is movable between a first position and a second position wherein in the first position the arm is positioned to engage the tip during movement of the nozzle along a selected path and to prevent movement of the tip along the selected path while permitting the nozzle to move along the selected path, so that the movement of the nozzle along the selected path causes the nozzle and the tip to disengage from each other, and wherein in the second position the arm is positioned to avoid engagement with the tip during movement of the nozzle.
Abstract:
A method of pipetting comprises (a) providing a pipette tip holder having a plurality of segregated compartments and a tip support member for supporting a plurality of pipette tips in the pipette tip holder, the tip support member configured to support a single pipette in tip each segregated compartment; (b providing a plurality of pipette tips in the tip support member; (c) removing a first pipette tip from a first segregated compartment; (d) using the first pipette tip to complete a pipetting operation and placing the first pipette tip into a segregated compartment that has not contained a used pipette tip; (e) subsequently removing the first pipette tip from the segregated compartment and using the first pipette tip to complete another pipetting operation; and, (f) replacing the first pipette tip into the pipette tip holder, whereby the first pipette tip, when placed in the segregated compartment, is segregated in the pipette tip holder to reduce the possibility of a fluid from the first pipette tip contacting other pipette tips in the pipette tip holder.
Abstract:
A neural colony forming cell (NCFC) assay is described. The assay allows one to distinguish neural stem cells from neural progenitor cells. In one embodiment, the present invention provides a method for identifying neural stem cells or neural progenitor cells comprising: (a) suspending neural cells in a semi-solid medium which supports the growth of neural cells; (b) plating the cells in the semi-solid medium at a density that allows for the production of colonies; (c) culturing the plated cells until size differences can be discerned between the colonies; and (d) estimating colony size wherein the larger colonies are likely produced by neural stem cells and wherein the small colonies are likely produced by neural progenitor cells In alternate embodiments, NSC can be distinguished from neural progenitor cells by determining the morphology or antigen expression of the colonies.
Abstract:
A method for preventing or inhibiting non-specific binding reactions between a detection reagent and an antigen in an immunological assay is described. The method involves using tetrameric antibody complexes that can bind to the antigen and are comprised of two monoclonal antibodies of a first animal species linked to two monoclonal antibodies of a second animal species that can bind the antibodies of the first animal species. Preferably, the antigen is an Fc Receptor and the method reduces the binding of a detection antibody with Fc receptors present on the surface of many cells.
Abstract:
A method for preventing or inhibiting non-specific binding reactions between a detection reagent and an antigen in an immunological assay is described. The method involves using tetrameric antibody complexes that can bind to the antigen and are comprised of two monoclonal antibodies of a first animal species linked to two monoclonal antibodies of a second animal species that can bind the antibodies of the first animal species. Preferably, the antigen is an Fc Receptor and the method reduces the binding of a detection antibody with Fc receptors present on the surface of many cells.
Abstract:
The present invention relates to methods for separating cells using immunorosettes. The method involves contacting a sample containing nucleated cells and red blood cells with an antibody composition which allows immunorosettes of the nucleated cells and the red blood cells to form. The antibody composition preferably contains bifunctional antibodies or tetrameric antibody complexes.
Abstract:
The present invention relates to antibody composition that are useful in preparing enriched cell preparations such as human hematopoietic progenitor cells and stem cells and non-hematopoietic tumor cells. The invention also relates to kits for carrying out the processes and to the cell preparations prepared by the processes.