In this experiment, the synthesized PQDs, monoclonal antibody, and PQD-antibody conjugation
were added to specimen insertion ports, named lanes 1, 2, and 3, respectively. To avoid the acidic quenching effect on PQDs (the destaining solution contains acetic acid, based on the anterior results), after running with SDS buffer for 90 min, the gel was imaged Selleck Thiazovivin on the Tanon 2500 gel imaging system with UV light (365 nm) in advance. To validate the coupling reaction, the gel was stained with Coomassie Brilliant Blue fast staining solution and washed with destaining solution. The stained gel was imaged again in white light. A comparison of the UV image with the image obtained by staining with Coomassie Blue is shown in Figure 3e. Apparently, in lane 1, the PQDs showed a clear bond which cannot be seen in bright fields (Figure 3e, left and right panels, lane 1). For monoclonal antibody, no signal can be detected in UV light but it is fairly visible
in bright fields (Figure 3e, left and right panel, lane 2). However, in the conjugation of PQD-antibody, the band clearly can be seen both in UV light and bright fields; both of the migration AZD1152 ratios in different imaging conditions are identical (Figure 3e, left and right panels, lane 3). This result suggested that the conjugation between monoclonal antibody and PQDs is successful. The mean coupling rates of BRCAA1 and Her2 were 75.52% and 73.37%, respectively, as shown in Table 2. Table 2 Coupling rate measurements of PQD-antibody BRCAA1 Her2 Total concentration (ng/ml) The residue concentration (ng/ml) Coupling rate (%) Total concentration (ng/ml) The residue concentration (ng/ml) Coupling rate (%) 1 10,000.0 2,204 77.96 10,000.0 2,582 74.18 2 10,000.0 2,749 72.51 10,000.0 2,865 71.35 3 10,000.0 2,566 74.34 10,000.0 2,773 72.27 4 10,000.0 2,177 78.23 10,000.0 2,309 76.91
5 10,000.0 2,545 74.55 10,000.0 2,785 72.15 Average 75.52 73.37 Effects of PQDs on cellular viability In order to evaluate the influence of PQDs to living cells (MGC803 and GES-1), the labeled cells (non-specific labeling by endocytosis) were passaged parallel with the original cells (non-labeled). In each passage, the fissional and developmental abilities of these cells Urocanase were estimated by MTT assay (repeated three times). Compared with the MTT results of PQD-labeled cells and the original cells, almost identical MTT values were gained in each generation (Figure 5). This consequence confirmed that the synthesized PQDs have negligible toxicity to the labeled cells and this is the essential requirement for further clinical applications [48, 49]. Figure 5 The MTT analysis results of MGC803 and GES-1 with and without PQD labeling. BRCAA1 monoclonal antibody-conjugated QDs for in vitro targeted imaging BRCAA1 antigen is a specific protein for the intracellular epitope of histone deacetylase Rapamycin complex subunit SAP180 expressed in the cytoplasm of the breast cancer cell line MCF-7 and gastric cancer cell line MGC803 [3].