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Kunming (KM) mice are the most widely used strain in China. However, authentic embryonic stem cells (ESCs) from KM mice have never been available, and this hampers the genetic manipulation of this valuable mice strain. In this study, we show that KM ESCs can be efficiently derived and maintained in chemically defined N2B27 medium with the presence of two small molecules PD0325901 and CHIR99021 (2i medium). These KM ESCs exhibit all features of ESCs, including long-term self-renewal ability, expression of key molecular markers (Oct4, Nanog, and Sox2), the ability to form teratomas, and the capacity to incorporate into the developing embryo and then transmit through the germ line.

Background and Objectives: The use of the manual hexadimethrine bromide (polybrene) test in routine cross-matching after accurately detecting cell grouping and irregular antibodies is prevalent in China. This article reports the importance of serum protein mediums in the performance of the manual hexadimethrine bromide test., Materials and Methods: Blood group O red blood cells and Blood group AB and Rh positive serum were collected at random from healthy blood donators, IgG anti-D serum separated from pregnant woman, then tested with each other by the manual hexadimethrine bromide methods in routine tests and some designed corresponding tests with IgG, IgM anti-D monoclonal diagnostic reagents and some serum protein components., Results: Red blood cells that were adjusted to 3-5% suspension by normal saline then only added in 0.7 ml low ionic medium (LIM) and two drops of polybrene solution adhere to the surface of test tubes' bottom when centrifuged, so it was difficult to perform the next approach, but the adherence disappeared when red blood cells' concentrations exceeded 20-30%. Rh positive red blood cells coated by anti-D have the same phenomenon. This adherence can be prevented by serum medium diluted from 1:128 to 1:1024 times by normal saline and hemoglobin medium diluted from 1:32 to 1:128 times, but not by albumin or immunoglobulin medium. The denary logarithm values of the greatest inhibited dilutions of serum and hemoglobin elution between antibody sensitizing red blood cells and the same pre-sensitizing red blood cells tests were no significant difference (P value > 0.05)., Conclusions: The whole serum or serum protein mediums are important factors that can influence successfully performance of the manual hexadimethrine bromide test. So appliance of the manual hexadimethrine bromide test to immunohematology laboratory, such as when performing titrations of serum or plasma, or when testing eluates for antibody activity, this adherence must be considered.