Intercalators direct imaging

Starting with the first IPCR study, gel electrophoresis retains its potential as a fast and easy method for end-point determination of DNA amplificate for IPCR assays [10, 24, 25, 29, 31, 35, 36, 38, 39, 64], Readout is performed by intercalation fluorescence markers (e.g., ethidium bromide) and photometric/densitometric quantification of band signal intensities. The direct addition of a double-strand specific intercalation marker to the PCR amplificate and subsequent measurement of fluorescence in microwells proved to be of insufficient sensitivity for the quantification of IPCR amplificate [37]. Alternative approaches, such as radioactive labeling during PCR and subsequent imaging [33], were carried out but are not well suited for routine clinical application because of additional methodological requirements. An advantage of gel electrophoresis is the possibility of simultaneous amplificate detection for multiplex IPCR [41] and the ability to detect nonspecific amplification products. 

EDS analysis after each wetting and drying cycle does not show any changes in the chemical composition. Because no cations or anions were dissolved in the water, no cation change or dissolution was possible at the temperatures employed in this study. XRD results showed an expansion of the basal spacing as a function of the relative humidity, due to the intercalation of water in the interlayers of the smectite. This effect could not be directly observed in the ESEM images. 

Figure 15.1. Transmission electron microscopy images of polypropylene filled with nano-clay to 5 wt%. (a) The combination of exfoliated and intercalated clay platelets is evident, (b) After stretching the platelets appear to be less curved and ai e aligned in the stretch-direction...

Very recently, Yu et al reported the synthesis of a series of PVA/MMT nanocomposites via in-situ intercalative polymerization with AIBN as initiator. Organic vinyl acetate monomers were first intercalated into the organically modified MMT galleries and followed by a one-step free radical polymerization. The prepared poly (vinyl acetate)/OMLS solution were then saponified via direct hydrolysis with NaOH solution to form PVA/MMT nanocomposites. The synthesized nanocomposites were characterized by FTIR, XRD, SEM, OPM, and TEM. XRD patterns and TEM images estabhshed the formation of mixed intercalated/exfoliated structure of the PVA/MMT nanocomposites. 

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