DNA that encodes elements for degenerate replication events by use of artificial nucleobases offers a versatile approach to manipulating sequences for applications in biotechnology. We have designed a family of artificial nucleobases that are capable of assuming multiple hydrogen bonding orientations through internal bond rotations to provide a means for degenerate molecular recognition. Incorp...

BACKGROUND: Clinical specimens are routinely fixed in 10% buffered formalin and paraffin embedded. Although DNA is commonly extracted from fixed tissues and amplified by PCR, the effects of formalin fixation are relatively unknown. Formalin fixation is known to impair PCR, presumably through damage that blocks polymerase elongation, but an insidious possibility is error prone translesion synthe...

The highly thermostable DNA polymerase from Thermus aquaticus (Taq) is ideal for both manual and automated DNA sequencing because it is fast, highly processive, has little or no 3'-exonuclease activity, and is active over a broad range of temperatures. Sequencing protocols are presented that produce readable extension products greater than 1000 bases having uniform band intensities. A combinati...

To investigate the influence of the pyrimidine 2-keto group on selection of nucleotides for incorporation into DNA by polymerases, we have prepared two C nucleoside triphosphates that are analogues of dCTP and dTTP, namely 2-amino-5-(2'-deoxy-beta-d-ribofuranosyl)pyridine-5'-triphosphate (d*CTP) and 5-(2'-deoxy- beta-d-ribofuranosyl)-3-methyl-2-pyridone-5'-triphosphate (d*TTP) respectively. Bot...

The use of glass–silicon chips for PCR analysis has been widely reported in the last decade, but there have been few systematic efforts to pin down the biochemical problems such systems bring forth. Here we report a systematic analysis of material-related inhibition and adsorption phenomena in glass–silicon PCR-chips. The results suggest that the previously reported inhibition of PCR by silicon...

We previously described in a paper published in BIOS an undergraduate lab activity involving the gene cloning, expression, and purification of Thermus aquaticus (Taq) DNA polymerase, an enzyme used in the polymerase chain reaction (PCR). Based on the large number of requests for biological materials and questions about the protocols this paper invoked, we explored methods to simplify the protei...

We studied the relationship among dopamine receptor D2 (DRD2) Taq I genetic polymorphism, caudate nucleus volumetry as measured using MRI and neuropsychological functions in 49 memory impaired older people. Compared with DRD2 A1 carriers, subjects homozygous for the DRD2 A2 allele performed poorer in a measure of general cognitive functioning (MMSE) and in long term verbal memory, and presented...