生物医学工程简介

INTRODUCTION OF BIOMEDICAL AND BIOENGNEERING,Three weeks courses,Gene and LifeGene Sequencing and BioinformaticsNanopore-the Next Generation Sequencer,An interesting question!,First, the chicken do? Or the egg ?,We can ask the chicken!,Structure of DNA,1A,2. Structure of dCTP,3. Base Tautomerism,Chargaff rules- A=T, G=C,helical,10 layer Lines BetweenCrossPatterns(10 ResiduesPer turn),Evidence for the Double Helix,1. Fiber Diffraction data:-Helical geometry-3.4 A spacing (1A = 10-10 m)-34 A pitch,NIH,1,Nitrogenous base,Sugar,Phosphate,-2-deoxyribose,2,Pyrimidines 嘧啶,Purines嘌呤,4,BaseAdenineGuanineThymineCytosine,Nucleoside(Deoxy)adenosine(Deoxy)guanosine(Deoxy)thymidine(Deoxy)cytidine,Nucleotide(d)A (mono, di-, tri) phosphate(d)G (mono, di-, tri) phosphate(d)T (mono, di-, tri) phosphate(d)C (mono, di-, tri) phosphate,6,1,9,PhosphodiesterBackbone,8,Pitch 34 ,Rise3.4 ,Width 20 ,Major Groove,Minor Groove,9,10.4 bp/turn,B-DNA: A rightHanded double helixWhy?,Twist 36,9,8.5 ,11.7 ,7.5 ,5.7 ,Major Groove,Minor Groove,10,11,From RNA to mRNA,In 1961, Brenner, s. Jacob, F., and Meselson used a series of experiments to prove that the mRNA is the messenger.,The creation of Central Dogma：,Francis Crick proposed the central dogma of molecular biology in a speech in 1957.He predicted the relationship between DNA,RNA and protein and expounded the transfer sub-hypothesis“(which become later tRNA),Classic Central dogma,20,遗传与变异,生物的亲代能产生与自己相似的后代的现象叫做遗传。亲代与子代之间、子代的个体之间，是绝对不会完全相同的，也就是说，总是或多或少地存在着差异，这种现象叫变异。遗传和变异是对立的统一体，遗传使物种得以延续，变异则使物种不断进化,21,Definition：,Chromosome geneDNAbase,22,,gene？,23,gene,intron,extron,extron,24,Gene & Circumstance,25,What about DNA and protein?who do the frist?,We can ask the RNA,he may know more about it.Or,in fact he does frist!,中心法则 genetic central dogma,27,DNA Sequencing,第一代,Sanger Sequencing,第二代,454焦磷酸测序法,SOLiD,SOLEX,第三代,1/20/2018,38,纳米孔,Storm et al. Nat. mater. Vol. 2 Aug. (2003),Li et al. Nat. Vol. 412, 12 July (2001),Bellay et al. Acc. Chem. Res. Vol.35, No.10, (2002),Nanotechnology, 17 , p: 32643267 (2006),49,What we do,Biosensor,Modification,NanoporeFabrication,Wafer Processing,Wafer Processing and Nanopore Fabrication play important roles in this process.,Fabrication and Application of Nanopore Sensors,Experimental method,I-V Curve,PSD (voltage = -150 mV),PSD (voltage = 150 mV),Surface Modification of Silicon Nitride Nanopore with CTAB,Materials and MethodsNanopore fabricationCTAB modification Current measurementResults and DiscussionVolt-ampere characteristics with different concentration of CTABElectrical noise characteristics with different concentration of CTABConclusionsConductivity increasesNoise variation,Materials and Methods,Microfluidic Set,CTAB,Volt-ampere characteristics,Electrical noise characteristics,58,Fig. 1 The fabrication of the silicon nitride membrane,59,Fig. 2 The diameters of nanopores were fabricated in different action times. The all images were taken by the SEM system. (a) Showing a nanopore of size 80 nm milled by focusing the ion beam on a spot for 40 s. (b) Showing a nanopore of size 55 nm milled for 30 s. (c) the nanopore of 50 nm drilled for 25 s. Fig. 2 (d) -(n) showing the diameters of pores in the action times are 20 s, 15 s, 10 s, 8 s, 5 s, 4.5 s, 4 s, 3 s, 1 s, 0.6 s, 0.5 s. (o) When the action time was 0.3 second, the pore was not through.,60,Theoretical and experimental study on capacitance characteristic of solid-nanopore,by Wang Xiaojuan,Theoretical calculations,Figure 1,Confirmation,Figure 2,Figure3,Experiment,CKCl=8.157276 pFCKCl+CTAB=9.923303pF,Introduction,Nanopore detectionDefecttunneling technology,Figure 1.Process of the nano-electrode fabricated on the surface of nanopore.,Experimental details,Figure 2. a.SEM image of metal wire after etched. b.SEM image of nano-electrode on the surface of the solid-state nanopore.,Results and discussion,a,b,Conclusion,Two nano-electrodes on the surface of the solid-state nanopore are fabricated sucessfully.The nanogap between two electrodes is larger than the diameter of nanopore.,2018/1/20,69,Introduction,A,2018/1/20,70,Experimental details,Figure 1. (a) Two dimensions of the nanopore-containing chip for TEM fabrication (diameter 2.8mm)on the left and FIB fabrication (5mm 5mm) on the right; (b) SEM image of nanopore of 35nm in diameter; (c) Experimental setup and the Cross-sectional view of the fluidic device.,2018/1/20,71,Results and discussion,Figure 2. (a) Parts of the nanopore ionic current trace at 400mv bias, after adding -DNA in the negative reservoir, current blocked events can be detected in the current trace. (b) The histogram of the nanopore current trace, Two peaks are visible, the high peak is represent for open-pore current while the low for blocked current. (c) An individual is event with an increased time resolution, each event is characterized by the translocation time td and current