Track Flashcards
How are white cells detected on the sysmex XN9000 track?
WDF Chanel, WNR chanel and WPC
WDF carries out the wbc differential count
WNR is used to count the number of NRBCs, basophils and leucocytes
The basophil count included in the wbc diff comes from the WNR chanel not the WDF chanel
WPC chanel is only used when blasts/abnormal lymphs are flagged
Laser flow cytometry -> forward scatter, side scatter
Lasercell and fluorocell reagents are used -> lasercell permeates the cell membranes allowing flurocell to stain the internal cell components
How is haemoglobin measured on the sysmex XN20
The direct measurement of haemoglobin using spectrophotometry
Uses the sodium laryl sulfate (SLS) method adapted to measure cyanide free haemoglobin
SLS lyses red blood cells releasing Hb from cells
SLS binds to the haem group of Hb forming SLS-HB which is a coloured compound
A colour change is observed at 555nm and is directly proportional to the Hb concentration measured by the detector
List the internal and external quality controls
Quality control level 1, 2, 3
Drift level 2
Xbar internal control
Inter analyser comparisons
External quality control
Qc blood film slide -> high wbcs
What steps need to be taken when there’s a reagent with a new lot number?
Reagent needs to be batch accepted
Isolate one analyser and run the reagent on it???
Run controls after loading reagent
If all parameters are within range then you can batch accept the reagent
Change sticker
What is the principle of the ESR?
Estimated sedimentation rate
A non specific marker of inflammation only really diagnostic of temporal arthritis
The time taken for rbcs to fall down/sediment through plasma to the bottom of a tube
A 4:1 ratio of blood to anticoagulant (sodium citrate) is necessary
The time taken for anticoagulated blood left to stand undisturbed to undergo rbc sedimentation
Single rbcs sediment slowly while aggregated clumps will settle more quickly
Light beam passes through sedivette and hits a detector behind the sample allowing the height of the rbc layer to be read
Measurement taken at 30 mins and 1 hour
