RFLP Standardization Report for Class I/SstI

We standardized data from three laboratories and encountered several problems for this enzyme–probe system. First, the DNA for sample #41 was not digested in all laboratories. Second, there were many discrepancies in the data in fragment assignment due to the difficulty, at times, of achieving complete digestion with this particular enzyme. Third, because of the small number of participating laboratories, it was difficult to achieve a consensus in certain samples of DNA which showed problems in more than one laboratory. To resolve these problems, we reevaluated the data or reassigned the fragments as much as possible. However, we regretfully had to delete the data in those cases we could not make any meaningful interpretation. For the most part, we were able to standardize the data in the same manner we used for the beta systems. But, we accepted measurements in the S filters because this system produced relatively small fragments.