Corrections in counting paired nuclei labelled with bromodeoxyuridine in tissue sections

Bromodeoxyuridine is finding increasing use as an alternative to, or in conjunction with, tritiated thymidine for labelling nuclei in DNA synthesis. Precise identification of labelled nuclei is possible, even when there is considerable overlap between neighbouring nuclei. In the sparsely labelled renal cortex of the normal male mouse, 'flash labelling' with bromodeoxyuridine shows single labelled nuclei at 1 h. At 24, 48 and 72 h after injection of bromodeoxyuridine, some labelled cells are seen to lie adjacent and such labelled pairs are presumed to be the result of cell division. Single labelled nuclei at 24, 48 and 72 h might indicate arrest in DNA synthesis or a prolonged G2 period, but it is important to recognize that a correction must be made for paired labelled nuclei in which one member is out of the plane of section. The factors involved in making such a correction are discussed and a correction table calculated. In the normal male mouse renal cortex, we show that nearly all cells labelled at 1 h had divided by 72 h.     

A simple method for incubation of tissue sections in immunohistochemistry

The construction of a simple "incubation chamber" is presented by which a homogeneous incubation of tissue sections with calculable amounts of immunoreagents is guaranteed. The incubation of large area sections, and parallel incubations of 10 slides are possible. As an example of application a case of alpha-1-antitrypsin deficiency in the liver is demonstrated.     

A simple method for incubation of tissue sections in immunohistochemistry

Summary The construction of a simple incubatin chamber is presented by which a homogeneous incubation of tissue sections with calculable amounts of immunoreagents is guaranteed. The incubation of large area sections, and parallel incubations of 10 slides are possible. As an example of application a case of alpha-1-antitrypsin deficiency in the liver is demonstrated.     

A tissue adhesive for paraffin sections intended for deamination with sodium hypochlorite

Summary It has been found that sections of paraffin-embedded tissue attached to glass slides with a nitrocellulose-based adhesive instead of albumen retain their original morphology and integrity when deaminated with solutions of sodium hypochlorite.     

A rapid method for staining semithin tissue sections embedded in araldite

A new rapid method is proposed for staining of semithin sections. The method involves the treatment of sections with a methylene blue solution with a slight heating for 1-3 minutes. The method allows to receive polychromatic contrast preparations, to save time and reagents. It also permits to avoid restaining effect. The preparations can be preserved for a long time in plastic media (e.g. in polystyrene) for light microscopy. A comparative analysis of the staining methods used in the electron microscopic practice is given.     

Polyethylene glycol embedded tissue sections for immunoelectronmicroscopy

Summary Several methods for tissue embedding in polyethylene glycol (PEG) were compared with regard to their applicability for pre-embedding immunoelectronmicroscopy. Existing embedding procedures gave unsatisfactory results and therefore a modified procedure was developed. This method, consisting of very brief tissue infiltration with PEG 1500, to which 3% water is added, allowed adequate tissue sectioning. Using these sections for preembedding immunoelectronmicroscopical localisation of glucagon in bovine pancreatic islets adequate ultrastructural morphology was obtained in combination with excellent preservation of peptide hormone immunoreactivity.Supported in part by grant no. PAL 52-77 of the Queen Qilhelmina Cancer Foundation