Abstract: A method for identifying and/or characterising a target cell in, and/or isolating a target cell from, a test sample which may contain said target cell, comprising the steps of 1) identifying and/or characterising any target cell in, and/or isolating any target cell from, the test sample by performing on the test sample a process involving interaction of a target cell selective reagent with a characterising component of the target cell, 2) providing a positive control sample comprising a positive control cell, wherein the positive control cell comprises said characterising component and is not identical to the target cell, 3) identifying and/or characterising the positive control cell in, and/or isolating the positive control cell from, the positive control sample by a process according to step 1 performed on the positive control sample, wherein the method for identifying, isolating and/or characterising the target cell is considered to have been performed correctly if the positive control cell is identified,

Abstract: A method of identifying embryonic or fetal red blood cells in a sample containing maternal blood cells and embryonic or fetal red blood cells or both, the method comprising determining, which cell or cells contain or express an adult liver component. A method of isolating embryonic or fetal red blood cells from a sample containing maternal blood cells and embryonic or fetal red blood cells or both, the method comprising isolating the cells which contain or express an adult liver component. A method of determining a fetal abnormality the method comprising identifying or isolating embryonic or fetal cells according to the above methods and analysing said embryonic or early fetal cells for said abnormality. Use of a means for determining whether a cell contains or expresses an adult liver component for identifying or isolating an embryonic or fetal red blood cell.

Abstract: A method of identifying embryonic or fetal red blood cells in a sample containiing maternal blood cells and embryonic or fetal red blood cells or both, the method comprising determining which cell or cells contain or express an adult liver component. A method of isolating embryonic or fetal red blood cells from a sample containing maternal blood cells and embryonic or fetal red blood cells or both, the method comprising isolating the cells which contain or express an adult liver component. A method of determining a fetal abnormality the method comprising identifying or isolating embryonic or fetal cells according to the above methods and analysing said embryonic or early fetal cells for said abnormality. Use of a means for determining whether a cell contains or expresses an adult liver component for identifying or isolating an embryonic or fetal red blood cell.