4 n maleimidomethyl cyclo hexanecarboxylic acid n hydroxysuccinimide ester

1-ethyl-3-(3-dimethylaminopropyl)-carbodimide hydrochloride (EDC), N-Hydroxysuccinimide (NHS), bovine serum albumin (BSA), Dimethyl sulfoxide(DMSO), O-(carboxymethyl) hydroxylamine hemihydrochloride (CMO), N, N-dimethylformamide (DMF), 2-Aminoethanol were provided from Sigma-Aldrich, Sephadex G-25 was bought from GE Health Life Sciences. Alkaline phosphatase (ALP) was procured from BBI Enzymes. 4-(N-Maleimidomethyl) cyclohexanecarboxylic acid N-Hydroxysuccinimide ester was purchased from Thermo. Lumigen APS-5 was purchased by Lumigen, Inc. tris (hydroxymethyl) aminomethane hydrochloride was from Sinopharm Chemical Reagent Co., Ltd. All chemicals were used without further treatment.
The phosphate buffer (pH 7.4) contained the 0.01 M KH₂PO₄ and 0.01 M Na₂HPO₄; the washing buffer (PBST): PBS buffer with 0.5 mL/L Tween 20.
The commercial HE4 ELISA assay kit was bought from Cusabio Biotech. Co., LTD. CEA, AFP, carbohydrate antigen 125 (CA125), carbohydrate antigen 153 (CA153), carbohydrate antigen199 (CA199) were bought from HyTest biotech Co. LTD. Elafin, Secretory leukocyte protease inhibitor(SLPI) were purchased from US Biological Life Sciences (America), Bilirubin, Hemoglobins, Triglycerides were bought from Solarbio Science &Technology Co., LTD. Rheumatoid factor was provided from Beijing Labo Biotech. Co., LTD.