although the mechanisms under which sex ratio is controlled in nature remain unknown, researchers have attempted to treat sperm in an effort to predetermine the sex of the offspring. the methods of sperm separation that have been repeatedly reported to isolate fractions rich in x- or y-chromosome bearing sperm are serum albumin gradient swim-up and flow cytometry. however, the ability of the se...

Although the mechanisms under which sex ratio is controlled in nature remain unknown, researchers have attempted to treat sperm in an effort to predetermine the sex of the offspring. The methods of sperm separation that have been repeatedly reported to isolate fractions rich in X- or Y-chromosome bearing sperm are serum albumin gradient swim-up and flow cytometry. However, the ability of the se...

Introduction: The amount of expression of BAX and BCL-2 genes in infertile men’s sperm as well as its association with sperm parameters and DNA fragmentation index is an issue which has not been studied yet. In this research, it is assumed that up-regulation of BAX and downregulation of BCL-2 are directly associated with sperm DNA fragmentation. Methods: After obtaining semen samples from the ...

A method for unambiguous determination of point mutations in genomic DNA, based on electrophoresis in thin capillaries, is reported here. The method is based on the principle of temperature gradient gel electrophoresis (TGGE), a variant of denaturing gradient gel electrophoresis (DGGE), and exploits the differential melting of mutant and wild-type PCR-amplified DNA fragments during electrophore...

Flow-through polymerase chain reaction (PCR) microfluidic systems for fast, small-volume DNA amplification on a single chip are significantly impacting medical and bioanalytical research. We have fabricated an improved, practical flow-through PCR chip by weighting a pressure-sensitive polyolefin (PSP) film onto a cyclo-olefin polymer (COP) substrate. The substrate was cut so as to produce micro...

Two-dimensional (2-D) gene scanning (TDGS) is a method for mutation detection based on the electrophoretic separation of PCR-amplified DNA fragments according to size and base pair sequence. The use of denaturing gradient gel electrophoresis (DGGE) as the second separation step provides virtually 100% sensitivity, while the 2-D format allows the inspection of multiple gene fragments simultaneou...

Here, we describe a three-step nested-PCR-denaturing gradient gel electrophoresis (DGGE) strategy to detect sulfate-reducing bacteria (SRB) in complex microbial communities from industrial bioreactors. In the first step, the nearly complete 16S rRNA gene was amplified using bacterial primers. Subsequently, this product was used as a template in a second PCR with group-specific SRB primers. A th...

We developed and tested a set of oligonucleotide primers for the specific amplification of 16S rRNA gene segments from cyanobacteria and plastids by PCR. PCR products were recovered from all cultures of cyanobacteria and diatoms that were checked but not from other bacteria and archaea. Gene segments selectively retrieved from cyanobacteria and diatoms in unialgal but nonaxenic cultures and fro...