A 1-step silver-staining technique, requiring only 2 min to perform, is described for the differential staining of nucleolus organizer regions. A protective colloidal developer is used to control the reduction of the silver.

Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: a 1-step method.

Analysis of wild-type and rad50 mutants of yeast suggests an intimate relationship between meiotic chromosome synapsis and recombination

Meiotic Pachytene Arrest in MLH1-Deficient Mice

A reliable technique for staining human chromosomal nucleolar organizers (NOR's) with silver solutions is described. The NOR's can be selectively stained dark brown by silver solutions leaving the chromosome arms unstained and available for counterstaining with orcein or Giemsa dyes. Unequivocal identification of chromosome pairs bearing NOR's can be achieved using fluorescent banding techniques followed by silver staining. The silver staining procedure for NOR's was simplified and standardized through control of the chemical and physical conditions during silver impregnation and developing.

An improved technique for selective silver staining of nucleolar organizer regions in human chromosomes

Though creation and characterization of water soluble luminescent silver nanodots were achieved only in the past decade, a large variety of emitters in diverse scaffolds have been reported. Photophysical properties approach those of semiconductor quantum dots, but relatively small sizes are retained. Because of these properties, silver nanodots are finding ever-expanding roles as probes and biolabels. In this critical review we revisit the studies on silver nanodots in inert environments and in aqueous solutions. The recent advances detailing their chemical and physical properties of silver nanodots are highlighted with an effort to decipher the relations between their chemical/photophysical properties and their structures. The primary results about their biological applications are discussed here as well, especially relating to their chemical and photophysical behaviours in biological environments (216 references).

Developing luminescent silver nanodots for biological applications

A simple ammoniacal silver staining procedure, designated Ag-AS, differentially stains the chromosomal locations of ribosomal DNA in certain mammalian species. This was critically demonstrated by Ag-AS staining of the nucleolus organizer regions in karyotypes of the same species and cell lines used for locating the ribosomal cistrons by DNA/RNA in situ hybridization. With Ag-AS, silver stained NORs (Ag-NORs) are visualized as black spherical bodies on yellow-brown chromosome arms. Ag-NORs were visualized throughout mitosis at the secondary constrictions in the rat kangaroo, Seba's fruit bat, Indian muntjac, and Rhesus monkey. The Chinese hamster and cattle have telomeric Ag-NORs, the mouse subcentromeric Ag-NORs, and the field vole Ag-NORs as minute short arms or choromosomal satellites. Ag-NORs occur at both secondary constrictions and at telomeres in the cotton rat. Variability in Ag-NOR pattern included differences in the number of Ag-NORs per cell within a cell population, size of Ag-NORs among chromosomes of a complement, and presence of Ag-NOR on particular chromosomes in two cell lines of the Chinese hamster. The available cytochemical data suggest that the Ag-AS reaction stains chromosomal proteins at the NOR rather than the rDNA itself.

Visualization of nucleolar organizer regions im mammalian chromosomes using silver staining

Improved methods for obtaining good cytological preparations from testicular tissues of Lepidoptera are described. Testes were pretreated with various hypotonic solutions, fixed in Carnoy's, and slides prepared using air dry-squash and cell suspension-air dry techniques. Air-dried slides were stained directly with Giemsa or treated with the C-band technique prior to staining. Well-spread chromosomes with good morphological characteristics were found in spermatogonial cells and spermatocytes of all stages. A detailed characterization of the mitotic chromosome complement and 1st meiotic division in males of the hesperiids Pyrgus oileus (L.), P. albescens (Plotz), and Lerema accius (Smith and Abbot) and the noctuids Trichoplusia ni (Hubner), Argyrogramma veruca (Fab.), and Prodenia ornithogalli Guenee are described.

http://aesa.oxfordjournals.org/content/aesa/69/4/764.full.pdf

Carll Goodpasture

Papers

Visualization of nucleolar organizer regions im mammalian chromosomes using silver staining

High-resolution Chromosome Analysis in Lepidoptera