Quality control samples for Cryptosporidium analysis with method 1623

SampleDate (mo/day/yr)% Recovery (RSD) witha:Method blank% IMS controls (RSD)
Viable oocystsColorSeedPositiveNegative
IPR samples
Avg39 (28)b40 (27)b67 (4)
OPR samples
Avg53 (10)c48 (13)c079 (5)0
  • a RSD is the relative standard deviation.

  • b Acceptable range for recovery is 24 to 100%; acceptable maximum RSD is 55%.

  • c Acceptable range for recovery is 11 to 100%.

  • d Slide was dropped and cracked, so counts are underestimated; this value was not used in average and statistical analyses.