Rat Immunoglobulin Isotyping ELISA Kit

In this paper, we report on the demonstration of a portable immunoassay system consisting of a small centrifugal microfluidic device driver (bento box) and a centrifugal microfluidic device made of polypropylene and fabricated by injection molding. The bento box consists of a cheap DC motor and an Arduino microcontroller. It has a simple structure and is the size of a bento box, that is, 150 x 150 x 100 (W x D x H) mm(3). The developed device can automatically execute an enzyme-linked immunosorbent assay (ELISA) process under a steady rotating condition because it was designed based on the principle of CLOCK, which we previously presented. Here, we first executed an ELISA using a system consisting of the bento box and a device made of polydimethylsiloxane (PDMS) and compared it with a servo-controlled device driver. It was confirmed that the results of the bento box were consistent with those of the servo-controlled device driver. The limit of detection (LOD) using the bento box was 0.759 ng ml(-1). Therefore, the controllability of the bento box was demonstrated. Next, we evaluated the injection-molded device through multi-step fluid control. We confirmed, through real-time observation of the device, that accurate flow control in the designed ELISA procedure was executed. Lastly, ELISA was employed for the measurements of mouse IgG using the system consisting of the bento box and the polypropylene device. The system performed all fluidic controls within 12 min; we confirmed the specificity of the system, and the LOD was 0.320 ng ml(-1).

PI3K plays multiple roles throughout the life of a B cell. As such, its signaling is tightly regulated. The importance of this is illustrated by the fact that both loss- and gain-of-function mutations in PI3K can cause immunodeficiency in humans. PIK3IP1, also known as TrIP, is a transmembrane protein that has been shown to inhibit PI3K in T cells. Results from the ImmGen Consortium indicate that PIK3IP1 expression fluctuates throughout B cell development in a manner inversely correlated with PI3K activity; however, its role in B cells is poorly understood. In this study, we define the consequences of B cell-specific deletion of PIK3IP1. B cell development, basal Ig levels, and T-independent responses were unaffected by loss of PIK3IP1. However, there was a significant delay in the production of IgG during T-dependent responses, and secondary responses were impaired. This is likely due to a role for PIK3IP1 in the extrafollicular response because germinal center formation and affinity maturation were normal, and PIK3IP1 is not appreciably expressed in germinal center B cells. Consistent with a role early in the response, PIK3IP1 was downregulated at late time points after B cell activation, in a manner dependent on PI3K. Increased activation of the PI3K pathway was observed in PIK3IP1-deficient B cells in response to engagement of both the BCR and CD40 or strong cross-linking of CD40 alone. Taken together, these observations suggest that PIK3IP1 promotes extrafollicular responses by limiting PI3K signaling during initial interactions between B and T cells.