Abstract
A I cm3 sample of tubules from testes is placed in 5 ml of 0.7% Na-citrate for 20-30 min, then 5 ml of glacial acetic acid is added, mixed well, and allowed to stand for 30 min. The mixture is centrifuged, the supernatant removed, and 3 ml of 3 M gluconic acid is mixed with the tissue and allowed to act for 3 hr. The gluconic acid is removed with a pipette and the tissue is suspended in 5 ml of a freshly made 1:1 absolute ethanol-glacial acetic acid mixture. The tissue is drawn into and discharged from a syringe several times through an 18, a 20, and finally a 22 gauge needle to separate and suspend the cells. The cells are centrifuged and resuspended several times in fresh fixative to remove the gluconic acid. Finally, the cells are suspended in sufficient fixative to give a smear of suitable density, and air-dried preparations are made, or the suspension may be stored at 0-5 C for several days. The cells can be stained by any of the usual stains for chromosomes. This technique results in the improved spreading produced by the air-drying technique and permits recovery of all stages of meiosis and mitosis present.