The quality control of cell banks using DNA fingerprinting

Cryopreservation of animal and human cell lines

The long-term storage of human and animal cell lines is a relatively new branch of the science of cryopreservation of living organisms. The need to maintain the increasing numbers of cell lines, as they started to emerge from research laboratories from the mid-1900s, necessitated a radical approach to the problem. The realization that they could survive cryopreservation, and that a slow rate of cooling is essential for this survival, led to the eventual discovery of cryoprotectants. Subsequent development of mechanical freezers, which can accurately control the rate of cooling, now allows cells to be cryopreserved at their maximum viability. This chapter outlines the essentials steps for the successful preparation, freezing, and storage of cell lines.

Molecular and Physiological Analysis of the Powdery Mildew Antagonist Pseudozyma flocculosa and Related Fungi

ABSTRACT A number of phenotypic and genotypic characteristics were used to ascertain the identity and diversity of Pseudozyma flocculosa, a natural antagonist of powdery mildews that has received little attention in terms of taxonomy. To this end, several putative isolates of P. flocculosa as well as several closely related species were analyzed. Ribosomal DNA sequences distinguished P. flocculosa from other Pseudozyma spp. and identified two previously unknown Pseudozyma isolates as P. flocculosa. Random amplified microsatellites revealed three distinct P. flocculosa strains among the tested isolates. Biocontrol properties and antifungal metabolite production were limited to the P. flocculosa spp. Results produced useful molecular markers to (i) distinguish P. flocculosa from other related fungi, (ii) identify different strains within this species, and (iii) aid in the construction of isolate-specific molecular tools that will assist in research and development of P. flocculosa as a biocontrol agent of powdery mildew fungi.

The Pearson product-moment correlation coefficient is better suited for identification of DNA fingerprint profiles than band matching algorithms

A database of DNA fingerprint profiles from permanently established human and animal cell lines was prepared with a computer program originally designed for numerical taxonomy of bacteria. Identifications of cell line DNA profiles were performed, both by the Pearson product-moment correlation coefficient and by band matching. Under the conditions used the Pearson product-moment correlation coefficient was consistently more reliable.