Marty, > The 636-10 is GaAs type PMT. Although they have better spectral > responses in the red than the 3896, 928, 1477 types, their gain is an > order of magnitude less. Thus, the match may not be optimal for the > preamp system gains that BD uses. Have you (or anyone else reading > this) had any experience with these PMTs? In 1996, we specified a type R636-10 for our MoFlo before the specs on the R3896 were available to us. It was supplied as Cytomation type H957-11. Hamamatsu's specs (http://www.hpk.co.jp/HP2E/main.html) show cathode radiant sensitivities at 800nm of about 15, 40 and 60 mA/W for types R928, R3896 and R636-10 respectively. I'm persuaded that the less than 30% cathode sensitivity improvement of the R636-10 over the R3896 is not worth the lower gain (about 20-fold). On the other hand, 200V more PMT volts should give a decade more gain. In fact we typically run our R636-10 PMT at 750V which is 100-200V more than the FITC and PE detectors. You can see an actual result at http://www.wehi.edu.au/cytometry/FCMexamples.html#apccy7 but we haven't done the comparison with any other PMT. Frank. Frank Battye, \ / < The Cytometry Laboratory Dora Kaminaris, \__/ <<<<< The Walter & Eliza Hall Institute Viki Lapatis, ------!!<<<<<<<< Victoria 3050, AUSTRALIA Jennie Parker and /!!\ <<<<< ph: 61_3_9345 2540 fax: 61_3_9347 0852 Catherine Tarlinton o !! \ < in:: "facs_copy@wehi.edu.au"
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