Research On Key Technologies Of New System For Cell Smear Preparation And Cell Release

The identification,isolation and enrichment of nucleated red blood cells from peripheral blood is in high demand in the field of non-invasive prenatal diagnosis.The nucleated red blood cells can be applied to the early diagnosis and screening of birth defects such as Down syndrome,neural tube defects,and single-gene diseases.However,most of the existing methods are based on immunoaffinity that depends on the specific antibodies,in which it limits the clinical application due to high cost,low separation purity,and tedious labor work.In order to achieve the monolayer cell smear and release of nucleated red blood cells from the peripheral blood in an effective way,we designed and manufactured an automatic cell smear preparation system and a laser focusing and microscopic imaging system for recognizing and releasing nucleated red blood cells.The details are as follows:(1)This paper described a home-made automated cell smear preparation system.First,the mechanical structure of the cell smear preparation system is designed,the motion control is developed based on the STM32 single-chip microcomputer,and the hydrogel membrane substrate smear was prepared by optimizing the pushing angle and speed parameters.Secondly,MXene,Two-dimensional material,was introduced into temperature-sensitive hydrogel gelatin,and the near-infrared light response was realized on the surface of hydrogel film by combining the near-infrared light thermal conversion characteristics of MXene.Last,the whole blood smear experiment was performed on the surface of the hydrogel basement membrane to optimize the blood smear parameters,prepare a releasable whole blood monolayer cell smear,and verify that the average cell density is increased by 19.3%compared with the standard smear.(2)A microscopic imaging and laser focusing system for the recognition and release of nucleated erythrocytes was constructed.First of all,an integrated optical path structure is designed and established,which can easily switch between bright field imaging mode and laser focus release mode.Secondly,in the bright field mode,the nucleated red blood cells are identified and located according to their special morphology.Thirdly,the light source of the 808 nm laser is focused on the surface of the cell smear through a collimator lens and a condenser lens to produce a photothermal effect for cell release.After the adjustment of the laser focusing system,the cell site-release area with a facula diameter of 300 ?m was finally obtained.