[Description of an economic and simple methods for the study of karyotyping in serpents]

We describe a method for the preparation of snake chromosomes in metaphase, based on the in vivo stimulation of leucocytes with crude phytohemagglutinin from Phaseolus lunatus and the in vitro blocking of mitosis with colchicine. It has the advantage of preserving the specimen alive without the complications of cell culture, and can be performed under field conditions.