7/15/94 JLP's field chromosome preparation 1- inject colchicine 0.01 me/g body weight inter-peritonially and leave for 1 hour 2- sacrifice the animal and take out the fibra and the femur and flush bone marrow into centrifuge tube w/ hipotonic KCl solution (0.075 M, 2.8g in 500 mL H2O) and let sit for 15' to 1/2 hour. + aspirate 3- pour solution through sieve into new centrifuge tube and centrifuge (40-50 turns in hand centrifuge) 4- pour off supernatant 5- add 1 me or 2 of freshly made fixative (1:3 ac.acético-glacial absolute metanol) and let sit for ± 1/2 hour at least 15' 6- aspirate and centrifuge 7- pour off supernatant and resuspend immediately and recentrifuge