生物化学技术

The isolation of high-quality cellular DNA is often a starting point for a variety of molecular-biology techmques These include Southern-blot analysis, PCR amphfication, and genomic-library construction (Fig. 1) It is often necessary to use the DNA from a single preparation for a number of d ...

Recombmant baculovinrus expression systems are now firmly established as one of the tools for producing foreign proteins in high yield wlthin a eukaryotlc environment The evolution of both single- and multiple-transfer vectors and different forms of baculovlral DNA has greatly str ...

The descrrptron of the first retrovtral packaging cell lme in the early 1980s mtroduced the technology by which a wide variety of different genes could be reliably and efficiently transduced into target cells using retrovnal vectors (I). Although the early prototype packaging systems we ...

Bacteriophage-based vectors, such as λ have been useful in creating gene llbrarles and in the expression of proteins However, a number of techniques used in molecular biology require DNA to be ina single-stranded form, such as chain termmatlon sequencing, ollgonucleotlde-directed mu ...

Plasmids, circular molecules of DNA that rephcate autonomously in a bacterial host cell, are widely distributed among prokaryotes They vary in size from a few to several hundred ktlobase pairs Although generally not essential to cellular survival, plasmids can confer a selecttve advan ...

The electrophoretic mobility shift assay (EMSA, also known as the gelshlft, gel retardation, or bandshift assay) is a technique that is widely used to study interactions between proteins and nucleic acids The assay is simple to perform, because it requires little specialized equipment and ...

The use of lectins (1) in electron microscoplcal histochemistry enables specific questions to be answered about the distribution of carbohydrates in cellular and extracellular components. For example, the occurrence of defined carbohydrate residues in particular stacks of the ...

Lectins are proteins or glycoproteins of nonimmune origin derived from plants, animals, or microorganisms that have specificity for terminal or subterminal carbohydrate residues. They are sensitive, stable, and easy-to-use tools. lectin histochemistry and cytochemistry can ...

Within the last 25 yr, the study of glycans, their structures, and their drstribution in tissues has emerged from relative obscurity to become a major theme of molecular and cellular biology: “glycobiology” (1). Glycans are major components of cellular surfaces (2,3), extracellular matric ...

A variety of staining reactions for the visualization of cellular and extracellular glycoconjugates at the light microscopic level are available that are based on the detection of carboxyl and sulfate groups or periodic acid reactive configurations (1,2). Starting in the late 1960s le ...

The use of lectins with different carbohydrate specificitres has demonstrated that there is a great diversity of carbohydrate residues, particularly in glycoconjugates of the cell membranes, but also in (sub)terminal carbohydrate residues of mucins and then precursors stored in ...

Cartilage is a highly specialized connective tissue that consists of cells embedded within an abundant extracellular matrix. The extracellular matrix of articular cartilage is composed of several types of collagens, proteoglycans, glycoproteins, noncollagenous protein ...

The purpose of diagnostic histopathology and cytology is to categorize a disease process and predict how that disease will affect the patient. Pathologists are now combining careful morphological evaluation of the structure of the cell nucleus and cytoplasm with immunohistochem ...

Pre-embedding lectin cytochemistry is one in a range of approaches used for analyzing the subcellular localization of glycoconjugate-classes, and thus enables the determination of the carbohydrate composition of cellular compartments. At the cell’s surface, the carbohydrate ...

Fixation of tissues for postembedding gold-lectin histochemistry calls for a fixative that preserves the ultrastructure of the tissue, has no inhibiting effect on lectin binding sites, and binds the glycoconjugates, which carry these lectin binding sites within the tissue so strong ...

Colloidal gold was developed as a probe for microscopy in the late 1970s. However, Roberts (1) had previously injected gold salts in living animals and detected the tissue-gold interactions microscopically by a photochemical method. With this method, metallic silver was deposited arou ...

Lectins are essential and omnipresent plant constituents. As many foods are of plant origin, the daily ingestion of lectins by both humans and animals is appreciable. For example, in an ad hoc survey, 53 edible plants were shown to contain lectins and approx 30% of fresh and processed food regularly co ...

Phytohemagglutinin (PHA), the lectin derived from red kidney been (Phaseolus vulgarus) causes reduced growth rates in several animal species, when incorporated at 0.5–5% of dietary protein. Lectin feeding results in diarrhea, impaired nutrient absorption, growth rate inhibitio ...

Proteins/glycoproteins from plants, particularly lectins, are more resistant to heat denaturation than animal proteins (1, 2). With legume seeds, whose lectin content is appreciable, this presents potentially serious problems in nutritional practice. Therefore, before they c ...

One of the major advances in neurobiology in the last two decades has been the development of neural tracing techniques that allow the investigator to unequivocally establish the precise pattern of connections between different populations of neurons. Early neuronal tracers were re ...