Hybridization spectrophotometric method

This can be accomplished using standard electophoretic and spectrophotometric methods. Researchers frequently note substantial variation in the quality of hybridizations obtained. Heavy background levels, scratches, and fingerprints are common contributors to hybridization variation. Once again, replicates for each RNA specimen permits discarding of bad arrays and serves to increase the precision of the data collected. 

For replicate copy number determinations of ribosomal RNA genes in maize and broad bean, we obtain a coefficient of variation of 8 -15% using the spectrophotometric method of DNA quantitation with hybridization Procedure A. The coefficient of variation is about 50% using the densito-metric method of quantitation with hybridization Procedure B. 

Wang et al used HRP entrapped into hybrid PVA/silica sol for the measurement of hydrogen peroxide. Their biosensor demonstrated a linear range in the concentrations 0.2-3.4 mM (curve at 3.4 mM in Fig. 4), with detection limit of 5 x 10 M. Furthermore, this biosensor exhibited high sensitivity (15 pA mM ) and fast response time (10 sec.). The results that were calculated from the calibration curve were in close agreement with the ones measured by a standard spectrophotometric method (Table 4). 

A hybrid SIA-FIA spectrophotometric method for the determination of total sulfite in white and red wines has been reported (Tzanavaras et al., 2009). The assay was based on the reaction of sulfite with o-phthalaldehyde (OPA) and ammonium chloride. Upon online alkalization with NaOH, a blue product was formed having an absorption maximum at 630 nm. Sulfite was separated from the wine matrix through an online gas-diffusion process incorporated in the SI manifold, followed by reaction with OPA in the presence of ammonia. The reaction mixture merged online with a continuously flowing of NaOH prior to detection. The SIA-FIA manifold is illustrated in Figure 2.8. 

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