Common methods applicable to flow cytometry make it possible to: (1) identify and quantify dead or dying cells, (2) reveal a mode of cell death (apoptosis or necrosis), and (3) study mechanisms involved in cell death. Gross changes in cell morphology and chromatin condensation, which occur during apoptosis, can be detected by analysis with laser light beam scattering. - [Read Flow Cytometry of Apoptosis Protocol]
Most biological specimens are relatively transparent, so details of internal and intracellular morphology are difficult to image in untreated living specimens using simple bright-field techniques. Fluorescence microscopy offers greater advantages and possibilities for increasing contrast and determining the specific localization of molecules in cells. Article outlines the three methods most commonly used to introduce an appropriate label into Drosophila tissue without perturbing the process. - [Read Fluorescent Reagents for Live Cell Imaging and Their Introduction into Cells]
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]
Zygotes can be identified by their unique morphology. They can be easily separated away from nonmated cells using a micromanipulator. This method provides an alternative to the selection of diploid cells on a medium that prevents the growth of haploid parent cells. - [Read Picking Zygotes Protocol]
An ideal method of tissue preparation ensures both good specimen morphology and that the target molecules are in the optimum state for probe access and hybridization. DNA:DNA in situ hybridization is usually carried out on chromosome spread preparations where chromosome and nuclei are released from cells and spread on a glass microscope slide. This method yields well separated and enlarged chromosomes with good morphology which can be analyzed in transmitted light or fluorescence microscopes. - [Read Preparation of Chromosome Spreads]
Protocol for the recovery of a highly viable fraction for use in fertilization. Protocol uses an iodinated density gradient medium to adjust the density of the raw ejaculate to approx 1.170 g/ml by mixing with a high density medium (Ï >1.26 g/ml) and loading it beneath a discontinuous gradient. - [Read Purification of viable bovine spermatozoa of normal morphology.]