ASSOCIATION FOR THE ADVANCEMENT

                               OF MEDICAL INSTRUMENTATION




25 November 1996

TO:          Members  of  ISO/TC  194/WG  12,  Sample   preparation   and   reference
             materials, and
             Conveners of all ISO/TC 194 Working Groups

FROM:        Donald Marlowe
             Convener of ISO/TC 194/WG 12

RE:          Review and analysis of ISO 10993-12:1996


I am pleased to confirm that ISO  10993-12:1996,  Biological  evaluation  of  medical
devices - Part 12: Sample preparation and reference materials, was  published  on  15
September 1996.     1 want to  thank  all  of  the  people  who  contributed  to  its
development.

Now that the document is in place, I think we could benefit from an analysis   of its
applicability.  Please review ISO 10993-12:1996 to see if it needs to be amended.  Can
the specimen preparation clauses in the other parts of  ISO  10993  now  be  deleted?
If not, do we need to amend Part 12 to reflect your practices?

With regards to reference materials, we list the known materials in Part  12.  Do  we
need to go to the next step of an interlaboratory comparison of  the  performance  of
these materials in the assays described in the parts of ISO  10993?  Should  we  list
other reference materials? Are the materials we listed  available  in  the  necessary
quantities?

These are topics we will discuss at the next meeting of ISO/TC  194/WG  12  in  York,
United Kingdom.  Please forward in writing  any  thoughts  and/or  comments  you  have
to Hillary Woehrle at the above address.  You can also send  a  fax  to  +703-276-0793
or e-mail to Hillary_Woehrle@AAMI.com.

Thank you for your input and we will see you in York.



cc:   W. Muller-Lierheim, Chairman of ISO/TC 194
      H.P. Keller, Secretary of ISO/TC 194
      Elizabeth A. Bridgman







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