A comparison of three different electron microscopical grade glutaraldehydes used to fix ovarian tissue



‘EM grade’ glutaraldehydes from three suppliers were tested for the following: (1) pH of stock solution, (2) 235/280 nm UV absorbance ratio, (3) milliosmolarity of 2% and 4% solutions, (4) quality of fixation produced in ovarian tissue by fixatives prepared from each stock solution. Low pH of the stock solution appeared to be the most detrimental factor in fixation. Fixatives with a low 235/280 nm ratio (between 0·18 and 0·67) did not give good fixation regardless of the pH of the stock solution. Fixatives made from stock solutions with a pH above 4 and a 235/280 nm ratio between 1 and 2 resulted in the best preservation of ultra-structure. Variations in milliosmolarity from one batch of stock solution to another were encountered, but appeared to have no correlation with the quality of fixation.; Received 1 October 1973; revision received 20 December 1973