Multiplex SNP typing by bioluminometric assay coupled with terminator incorporation (BATI)

A multiplex single-nucleotide polymorphism (SNP) typing platform using ‘bioluminometric assay coupled with terminator [2′,3′-dideoxynucleoside triphosphates (ddNTPs)] incorporation’ (named ‘BATI’ for short) was developed. All of the reactions are carried out in a single reaction chamber containing target DNAs, DNA polymerase, reagents necessary for converting PPi into ATP and reagents for luciferase reaction. Each of the four ddNTPs is dispensed into the reaction chamber in turn. PPi is released by a nucleotide incorporation reaction and is used to produce ATP when the ddNTP dispensed is complementary to the base in a template. The ATP is used in a luciferase reaction to release visible light. Only 1 nt is incorporated into a template at a time because ddNTPs do not have a 3′ hydroxyl group. This feature greatly simplifies a sequencing spectrum. The luminescence is proportional to the amount of template incorporated. Only one peak appears in the spectrum of a homozygote sample, and two peaks at the same intensity appear for a heterozygote sample. In comparison with pyrosequencing using dNTP, the spectrum obtained by BATI is very simple, and it is very easy to determine SNPs accurately from it. As only one base is extended at a time and the extension signals are quantitative, the observed spectrum pattern is uniquely determined even for a sample containing multiplex SNPs. We have successfully used BATI to type various samples containing plural target sequence areas. The measurements can be carried out with an inexpensive and small luminometer using a photodiode array as the detector. It takes only a few minutes to determine multiplex SNPs. These results indicate that this novel multiplexed approach can significantly decrease the cost of SNP typing and increase the typing throughput with an inexpensive and small luminometer

The nuclear hexadecapole interaction of iodine-127 in cadmium iodide measured using zero-field two dimensional nuclear magnetic resonance

Two dimensional nuclear quadrupole correlation spectroscopy has been used to measure simultaneously the two nuclear spin transition frequencies for the iodine resonance of cadmium iodide at zero magnetic field. Because of the layer structure and resultant polymorphism in this substance, conventional zero-field NMR spectra are inhomogeneously broadened by several hundred kHz. However, the 2D spectra obtained by our method are subject only to homogeneous line-width, which for this compound is of the order of 5 kHz. This greatly increased precision allows more accurate evaluation of the nuclear hexadecapole coupling- in cadmium iodide; which we measure as 0.216 ±0.514 kHz (i.e., indistinguishable from zero). This gives a maximum value of the nuclear hexadecapole moment several times lower than that recently reported for the same nucleus in potassium iodide

WTC2005-63602 EFFECTS OF TUBE DIAMETER ON FRICTIONAL CHARACTERISTICS OF CARBON NANOTUBES

ABSTRACT Frictional characteristics of carbon nano-tube powders were measured and compared with those of conventional solid lubricants, MoS 2 and graphite. In linear one way sliding tests, a multi-wall CNT showed similar coefficient of friction with graphite. It was also showed that the larger the particle sizes, the smaller the COF for those powders. A sliding model considering CNT geometry was proposed. INTRODUCTION Carbon nano-tubes (CNTs) are now studied extensively for mechanical applications to utilize their high strength and high elastic modulus in addition to electrical and thermal applications One report showed the coefficient of friction (COF) of 0.3 for a multi-wall CNT (MWCNT) fil