Objective: To investigate the method of chromosome preparation of tumor cells and bio-engineering cells mutated by outer space, and to analyze the abnormal changes of number and structure of chromosomes.

The effects of sucking different amounts of cytoplasm and with or without the first polarbody as indication during enucleation on the enucleation rate in the mouse oocyte were stud-ied by means of McGrath and Solter s technique for enucleation and a modified technique forchromosome preparation.

The preparation of chromosome is a frequent and an important technique in medical genetics.

Comparison of several chromosome preparation methods in sea perch Lateolabrax saponicus;

A technique for chromosome preparation using wheat coleoptile cells;

Using the enriched lymphocytes to prepare chromos ome, we get the high split-index chromosome preparations without the interferenc e of the erythrocytes.

On the bases of studies on techniques in chromosome preparation, meiotic behaviours of pollen mother cells (PMCs) and development of male gametophyte were observed on autotetraploid and diploid broccoli, which laid bases for genetic breeding of polyploid broccoli.