**2.1.4 Solid phase protein chip technology**

The solid phase protein chip technology usually refers to the sample separation part of the SELDI system. The SELDI can not only use the enzyme, antibody, receptor and DNA as the sorting basis of chips, but also take chemical mediators of different natures as the protein sorting basis according to the different chemical natures of proteins, thereby to reduce the requirement on the sample purification and enlarge the sorting range of samples. SELDI chips can be divided into the chemical surface chips and biological surface chips according to the detection purpose. The former include hydrophobic surface (H4), normal phase (NP), weak cation exchange (WCX), strong anion exchange (SAX) and immobilized metal affinity capture (IMAC) and the latter include antibody-antigen surface chips, receptor-ligand surface chips, enzyme-substrate surface chips and DNA-protein surface chips, specifically for detecting the corresponding polypeptide molecules.

### **2.1.5 Liquid phase protein chip technology – Magnetic bead**

The magnetic bead is a new multifunctional reagent developed in recent years and widely used in biomedicine. Owing to diversified surfaces of macromolecular coat, magnetic beads can be coupled with various biologically active substances (like antibody, antigen, receptor, enzyme and nucleic acid), which can be fixed to the magnetic beads to further identify corresponding antigen or antibody, ligand, substrate, nucleic acid in the reaction medium, thereby to realize separation or detection. The results show magnetic beads have functions of both the carrier and separation performer. They can simplify complicated operations by utilizing the physical, chemical and biomedicine principles, thereby to greatly shorten the period of conventional test. Different from protein chips, magnetic beads are composed of many magnetic spherical granules, which provide them with greater surface area and enable them to combine more specific proteins and to have higher sensitivity and accuracy.

To be detailed, the disease associated differential protein liquid chip SPE-C magnetic beads; hydrophobic MB-HI C 1 (suitable for purification and enrichment of proteins more-than-20kDa), MB-HI C 3 (suitable for purification and enrichment of 8-20kDa proteins), MB-HI C 8 (suitable for purification and enrichment of 1-10 kDa proteins/polypeptide), MB-HI C 18 (suitable for purification and enrichment of less-than-4kDa polypeptide); metal affinity magnetic beads include MB-IMAC-Fe (for capture and enrichment of phosphorylation proteins) and MB-IMAC-Cu (for the capture and enrichment of specific affinity

particular, structures with the peptide sequences containing His-X-X-X-His are easiest

Capillary electrophoresis (CE) was invented by Hjerten at the 1960s on the basis of the conventional electrophoretic technology and improves the electrophoresis efficiency by dozens of times by replacing the large electrophoresis tanks with the capillaries. This technology developed rapidly from 1980 and became a good tool for separation and determining the nature of polypeptides and protein substances by bio-chemical analysts and biochemical scholars. By application principles, CE can be divided into: Capillary Zone Electrophoresis (CZE), Capillary Isoelectric Focusing (CIEF), Capillary Gel Electrophoresis

The solid phase protein chip technology usually refers to the sample separation part of the SELDI system. The SELDI can not only use the enzyme, antibody, receptor and DNA as the sorting basis of chips, but also take chemical mediators of different natures as the protein sorting basis according to the different chemical natures of proteins, thereby to reduce the requirement on the sample purification and enlarge the sorting range of samples. SELDI chips can be divided into the chemical surface chips and biological surface chips according to the detection purpose. The former include hydrophobic surface (H4), normal phase (NP), weak cation exchange (WCX), strong anion exchange (SAX) and immobilized metal affinity capture (IMAC) and the latter include antibody-antigen surface chips, receptor-ligand surface chips, enzyme-substrate surface chips and DNA-protein surface chips, specifically

The magnetic bead is a new multifunctional reagent developed in recent years and widely used in biomedicine. Owing to diversified surfaces of macromolecular coat, magnetic beads can be coupled with various biologically active substances (like antibody, antigen, receptor, enzyme and nucleic acid), which can be fixed to the magnetic beads to further identify corresponding antigen or antibody, ligand, substrate, nucleic acid in the reaction medium, thereby to realize separation or detection. The results show magnetic beads have functions of both the carrier and separation performer. They can simplify complicated operations by utilizing the physical, chemical and biomedicine principles, thereby to greatly shorten the period of conventional test. Different from protein chips, magnetic beads are composed of many magnetic spherical granules, which provide them with greater surface area and enable them to combine more specific proteins and to have higher sensitivity and accuracy. To be detailed, the disease associated differential protein liquid chip SPE-C magnetic beads; hydrophobic MB-HI C 1 (suitable for purification and enrichment of proteins more-than-20kDa), MB-HI C 3 (suitable for purification and enrichment of 8-20kDa proteins), MB-HI C 8 (suitable for purification and enrichment of 1-10 kDa proteins/polypeptide), MB-HI C 18 (suitable for purification and enrichment of less-than-4kDa polypeptide); metal affinity magnetic beads include MB-IMAC-Fe (for capture and enrichment of phosphorylation proteins) and MB-IMAC-Cu (for the capture and enrichment of specific affinity

combined to the metal ion affinity column, featuring good purification effect.

(CGE) and Micellar Electrokinetic Electrophoresis Chromatography(MECC).

**2.1.3 Capillary Electrophoresis** 

**2.1.4 Solid phase protein chip technology** 

for detecting the corresponding polypeptide molecules.

**2.1.5 Liquid phase protein chip technology – Magnetic bead** 

proteins/polypeptides); ion exchange magnetic beads include MB-WCX (purification and enrichment of acid proteins with the cation-exchange chromatography technology) and MB-WAX (purification and enrichment of basic proteins with the anion-exchange chromatography technology); glycoprotein magnetic beads include ConA and ConB (for purification and enrichment of glycoprotein); the immune fishing liquid chips include immune affinity magnetic bead ProteinG (the ProteinG on the magnetic bead can combine with any one antibody, for screening specific antigens).
