Archive for category biochemistry
Molecular Cloning
Posted by admin in biochemistry on July 22, 2009
Molecular cloning refers to the technique of isolating and copying a specific DNA sequence to a host. It serves an amplification process and can be applied to anything involving a DNA sequence (which includes genes, promoters, oligonucleotides, and random fragments).
Classical procedures of cloning involve isolation of the DNA of interest, transfection/transformation, and screening/selection.
Phagocytosis Assay: Introduction and protocol
Posted by admin in biochemistry on July 18, 2009
A phagocytosis assay is simply a method of measuring the phagocytosis activity (which is the cellular process of engulfing solid particles, including bacteria, dead tissue cells, and small mineral cells.)
In short, the assay is prepared by incubating stained phagocytic cells (the ones that are supposed to be engulfed) along with macrophages, and the result may be counted with the use of a microscope. This can not only indicate the strength of the immune system, but also identify what types of cells are being engulfed.
Flow Cytometry
Posted by admin in biochemistry on July 18, 2009
Flow cytometry is a technique for measuring phonotypical, biochemical, or molecular characteristics of cells by passing suspended cells through a detection apparatus. Monochromatic light (usually in the form of lasers) are used as a light source, and the scattering and fluorescent pattern received in individual detectors along the cytometer are used to provide much useful information.
Flow cytometers can analyze several thousands of cells per second, separating those with specific properties and measures set parameters. It is similar to a microscope, except each individual cells are examined and automatic quantification of parameters are allowed. Spectrophotometry measures the percent transmission (and absorbance) instead of fluorescence of cells.