Karyotype evaluation among young horse populations in Poland.

Five hundred young horses of the following breeds: Thoroughbred, Silesian, Malopolska, Wielkopolska, Polish Konik, Hutsul, Shetland Pony, Half-bred Anglo-Arabian, Noble Half-bred, Fjord and crosses were cytogenetically investigated. Chromosome preparations obtained after lymphocyte culture were analysed using conventional Giemsa staining and CBG-banding methods. In the case of abnormalities GTG-banding as well as FISH technique were applied. In ten mares different karyotypic abnormalities were diagnosed. One mare showed chromosome chimerism (64,XX/64,XY), eight had sex chromosomal aneuploidy (one in pure line 63,X and seven in mosaic form 63,X/64,XX) and one presented autosomal aneuploidy with mosaicism (64,XX/65,XX,+31). The influence of sex chromosome abnormalities on fertility and the possible utilisation of karyotypic control in any selection programme are discussed.

Economic considerations important in the scale-up of an ovalbumin separation from hen egg-white on the anion-exchange cellulose DE92.

The scale-up of the separation of hen egg-white proteins has been investigated using Whatman DE92 anion-exchange cellulose. Having developed suitable chromatographic conditions, a maximum binding capacity of 100 mg protein/ml packed DE92 was determined in a 25-ml column. The process was scaled up 1000-fold and the influence of batch and column techniques on the chromatographic step assessed. Data indicate column processes to be more efficient than batch in the adsorptive stage.

A simplified process for large-scale isolation of IgG from goat serum.

Immunoglobin G (IgG) is routinely used in many immunoassay systems. Whilst various laboratory-scale procedures exist for the isolation of IgG from host serum few are appropriate for scale-up. We have previously reported the improvement of an existing process for isolation of IgG from goat serum at laboratory scale (Schwartz et al., 1986) and in this study we took those improvements to pilot-scale and significantly reduced the process time and associated costs. Media fouling was reduced and product yield enhanced by utilisation of a guard column of the appropriate geometry. Isolation of pure IgG by anion-exchange chromatography was improved by selection of a suitable mobile phase and column loading parameters. Using a 10 1 column of QA52, 36 g of immunoelectrophoretically pure IgG was isolated from 7.2 1 of goat serum at an overall yield of 58%. Product recovery and purity were reproducible at pilot-scale under these conditions. A procedure for media clean-in-place (CIP) is described which also effects sterilisation and depyrogenation of the column and media.

Chromatography of hen egg-white proteins on anion-exchange cellulose at high flow rates using a radial flow column.

The influence of column configuration on the separation of hen egg-white proteins using Whatman DE52 and QA52 anion-exchange cellulose has been investigated. Using a 100 ml volume axial flow column (6.6 cm x 4.4 cm i.d.) we achieved flow rates of up to 25 ml/min i.e. 15 bed volumes/h after which higher flow was restricted due to pressure constraints within the system. Under radial flow conditions using a 100 ml column flow rates of up to 150 ml/min i.e. 90 bed volumes/h were achieved using DE52 and QA52. While chromatographic resolution was superior under axial flow at the lower flow rates excellent resolution was maintained at up to 150 ml/min using the radial flow column. This is a consequence of the fast kinetics of adsorption/desorption exhibited by DE52 and QA52. The data indicate that it is the column configuration and not the cellulose matrix which influences flow performance.