DNA detection in hair of transgenic mice - a simple technique minimizing the distress on the animals

The breeding of transgenic animals requires that each individual offspring be analysed for integration of transgenic deoxyribonucleic acid (DNA), unle ss exclusively homozygous animals are mated. The standard protocol for iden tification of transgenic animals (Hogan et al. 1994) is based on tissue sam ples and preparation of chromosomal DNA including proteinase K digestion an d phenol/chloroform extraction. The procedure described here represents a m uch simpler and faster method to screen offspring for the transgene DNA. It is based on the use of hair bulbs as sample material, which can be directl y used for polymerase chain reaction (PCR) after alkaline lysis. This proto col allows large numbers of animals to be easily screened in a minimum amou nt of time. A unique advantage though, is the reduction of the distress cau sed to the animals. With respect to the 3Rs (Replacement, Reduction, Refine ment), and because of technical advantages this method may replace ear or t ail clipping.