A silver stain to demonstrate neurofibrillary tangles, nerve fibers and senile plaques in Alzheimer's disease. The nerve fibers are sensitized with a silver solution. The sections are treated with ammoniacal silver, and then reduced to a visible metallic silver. - [Read Bielschowsky Technique for Senile Plaques Protocol]
Mice fed with the cytohesin inhibitor SecinH3 for two days develop hepatic insulin resistance that can be identified by reduced liver glycogen levels, increased serum insulin and ketone body levels and decreased serum non-esterified fatty acid. To confirm the presence and identity of SecinH3 in mouse liver, we extracted the compound from liver homogenates with chloroform and identified it by LC/MS. - [Read Extraction of the SecinH3 from Mouse Liver Protocol]
This cDNA synthesis system simplifies your work dramatically. All reaction components are premixed and lyophylised. You have to add your RNA and (for Your-Prime beads) the primer. Another advantage of the system is a little number of pipetting steps required, and therefore reduced risk of Rnase contamination and RNA degradation. - [Read First strand cDNA synthesis with Ready-To-Go Beads Protocol]
Forward genetics is used to identify genes that are involved in particular biological processes. For example, genes required for disease resistance can be found by identifying mutants with reduced or increased disease resistance, genes that control flower development can be identified by searching for mutants with altered flower morphology, and genes encoding enzymes for tryptophan biosynthesis can be identified by searching for mutants that require exogenous tryptophan for growth. - [Read Forward Genetics in Arabidopsis: Finding Mutations that Cause Particular Phenotypes Protocol]
Lowry Protein Assay. The Lowry procedure is one of the most venerable and widely-used protein assays, being first described in 1951 [Lowry et al., J. Biol. Chem. 193: 265-275 (1951)]. Under alkaline conditions, copper complexes with protein. When folin phenol reagent (phospho-molybdic-phosphotungstic reagent) is added, the Folin-phenol reagent binds to the protein. Bound reagent is slowly reduced and changes color from yellow to blue. P.J. Hansen, Dept. of Animal Sciences, University of Florida. - [Read Lowry Protein Assay]
Ice tea has a complex composition, which leads to reduced filterability, and a decrease in sample throughput. Its composition can generate background or false positive signals. It is also well known that ice tea contains molecules that can inhibit the bioluminescence reaction, which can generate false negative results. The aim of this study was to develop a protocol that was able to neutralize these affects and enable faster detection of contamination. - [Read Microbial Detection in Ice Tea Using the Millipore Milliflex Rapid Microbiology Detection System]
The physiological reactions of mitochondria and chloroplasts can be reduced to a series of electron transfers, catalyzed by specific enzymes found within the organelles. Thus, we can study the component processes of photosynthesis and respiration by isolating the organelles and measuring specific enzyme activity associated with that organelle. - [Read Photosynthesis and Respiration - Introduction]
Single-step technique, cells are homogenized in guanidnium thiocyanate and the RNA is purified from the lysate by extraction with phenol:chloroform at reduced pH. Many samples can be processed simultaneously and speedily. The yield of total RNA depends on the tissue or cell source and is generally in the range of 4-7 µg/ml starting tissue or 5-10 µg/106 cells. IMPORTANT: Prepare all reagents used in this protocol with Diethyl pyrocarbonate (DEPC)-treated H2O. - [Read Purification of RNA from Cells and Tissues by Acid Phenol-Guanidinium Thiocyanate-Chloroform Extract]
In an attempt to accurately measure DNA content with simultaneous preservation of cell surface markers, we have utilized gentle ethanol treatment techniques, which permeablize cells with minimal loss of surface antigen expression and antibody-antigen association. For some cell types, the presence of apoptotic cells based on reduced DNA content can also be detected. One such technique employs the addition of ethanol to cells previously resuspended in high concentrations of fetal bovine serum... - [Read Simultaneous Analysis of DNA Content and Surface Immunophenotype Protocol]
Protargol-S (silver proteinate) is used with the addition of copper metal. The copper replaces the silver in the connective tissue, allowing a greater differentiation between the nerve fibers and the connective tissue. The silver is reduced with hydroquinone to the visible metallic form. The sections are toned with gold chloride, the gold chloride is reduced with oxalic acid, increasing the deposit of metallic gold on the sections. - [Read Staining of Nerve Fibers Protocol]
DNA microarrays are an ordered arrangement of DNA molecules complementary to genes of interest that are "spotted" by robotic equipment onto a glass slide substrate. The expression of genes in cells can be monitored with microarrays by preparing cDNA from the mRNA of cells of interest and measuring the hybridization to the microarray. This protocol describes the labeling of genomic DNA for use as a probe for hybridization to the cDNA spotted on the array.
This protocol describes the electroporation of the BMH 81-17 mut S strain that is recommended for tranformation of the site directed mutagenesis of dsDNA (See Protocol on Site-Directed Mutagenesis on Double Stranded DNA). BMH 81-17 mut S are a mismatch repair defective (mut S) Escherichia coli strain. The probability that the two mutations will cosegregate during the first round of DNA replication is increased in this strain.