Cea human elisa kit

To optimize measurement of serum exosomal CEA, the effects of concentration of the samples, formulation of the solvent, and thawing temperatures for frozen samples were evaluated. Samples from eight patients and eight normal healthy subjects were used. Each patient’s exosome pellet was resuspended using 250 μl of Milli-Q water (1×), 50 μl of Milli-Q water (5×), 250 μl of 1% BSA (1×) or 50 μl of 1% BSA (5×). Frozen serum samples from the same participant were thawed at 4, 25, and 37°C. An EXOCET Exosome Quantitation Kit(System Biosciences) and a CEA (human) ELISA kit (Abnova) were used for the quantitation of each exosome sample and the measurement of exosomal CEA concentrations, respectively.

Whole blood was collected into serum-separating tubes and then centrifuged at 1000 ×g for 10 min at 4°C. Serum was distributed in 250-μl aliquots into Eppendorf tubes and frozen at –20°C until analysis. Frozen serum samples were thawed at 4, 25, or 37°C for 30 min. A total of 63 μl of ExoQuick Exosome Precipitation Solution (System Biosciences, Palo Alto, CA, USA) was added to each thawed 250-μl serum sample, which was then incubated at room temperature for 30 min. The serum/ExoQuick mixture was centrifuged at 1500 ×g for 30 min at 4°C. The supernatant was aspirated, and the exosome pellet was resuspended using water or 1% bovine serum albumin (BSA). A CEA (human) ELISA kit (Abnova, Taipei City, Taiwan) was used in our assay.