State the final dilution obtained when using the RBC Unopette System.
List the reagent in the diluting fluid used in the RBC Unopette System.
1.99 mL normal saline and sodium azide in purified water
State the normal values for erythrocyte counts for adults, children, and newborns.
adult male: 4.6-6.2 * 10^5/ul
adult female: 4.2-5.4 * 10^6/ul
children: normal values slightly lower than adults
newborns: 4.8-6.0 * 10^6/ul
What errors can be caused by the apparatus?
chipped pipette tips, non-optically plane cover glasses, dirty chamber/coverglass, inaccurate rulings on chamber
What errors can be caused by personal technique?
not thoroughly mixing blood, inaqequate mixing of diluted specimen, failure to discard first few drops, counting cells inaccurately, not loading chamber properly, calculation error, clerical error
What errors are inherent in hemacytometry?
"field errors", statistical error
How does a field error occur?
relates to the random distribution of cells on the counting chamber
How does a statistical error occur?
when total number of cells is too low to give statistical confidence in result (reduced when large number of cells are counted)