Manual Reticulocyte Counts Flashcards
In the reticulocyte cell stage there are small amounts of______ that remains in the RBC. 
RNA
In order to detect the presence of RNA the RBCs must be stained while they are still __________.
What is this process called?
Alive
Supravital staining
What is the overall process for manual reticulocyte count?
-whole blood (EDTA) Is incubated with the supravital stain, new methylene blue.
-Smears are prepared
-Smears are observed using a Miller disk
-The number of retics in 1000 RBCs is counted, and then this number is divided by 10 to obtain the retic count as a percent.
What is placed inside the microscope ocular‘s to aid in the Retics counting process?
Miller disk 
-Will appear as two squares, one inside the other and the Smaller square will be exactly 1/9 the size of the larger square
How much smaller is the inner square in the Miller disk? 
1/9 the size of the larger square
Where is an acceptable area to use the Miller desk on a blood smear?
An area where the RBCs are close together but not overlapping, and where the retics appear to be well stained
-The RBCs will be a light to medium green color, and the RNA present will stain as widely scattered deep blue particles
To be considered a reticulocyte, the RBC must contain ______ or more Blue staining particles
2
Beware, many retic slides contain ________ artifact; These are shiny and easily confused with true reticulum.
Water
*Be especially careful if a cell is a retic and has water artifact! *
Using the 100 X oil immersion objective, you move through successive fields and count all of the…..
Erythrocytes (Both retics and plain RBCs) in the small square of the field as “RBCs”
Then count all the retakes seen in both squares as “retics”, continue this way until *111(+or-) 4 RBCs are counted
*** remember: A retic in the small square is counted as….
Both an RBC and a retic!
What do you count in the small square of the Miller desk?
And what do you count in the larger square plus the small square?
RBCs and retics as “RBCs”
All retics in both squares
- Continue this way until 111+ or -4 RBCs are counted* Whatever number of retics was counted during this process is used in the calculations*

We want to report our number of retics as a percentage. what is the easiest way to do this?
Take the total number of retics you counted in all of the whole (larger) Squares and divide by 10 
What do you do about a cell that sits on the line?
Always count those cells sitting on the top and left lines
“Top Left Count, TLC method)
Reticulocyte manual counts should be done how many times?
And when you compare the sets of results they should be +/- _____% 
2
0.5% (if this is the case, Average the two numbers)
What is the normal reticulocyte percentage for adults, children, and newborns?
Adults 0.5-2.0%
Children 1.0-3.0%
Newborns 2.0-6.0% 
How do you calculate ARC?
Reticulocyte (%) x RBC count (x10^12)
Divided by 100
And what does ARC stand for?
Absolute reticulocyte count
What does CRC stand for? 
Corrected reticulocyte count (Reticulocyte index) 
Why would a corrected reticulocyte count be performed?
When a specimen has a low hematocrit.
(The percentage of reticulocytes may be falsely elevated due to the few RBCs in the blood. A correction factor is used, considering the average normal hematocrit to be 45%) 
How do you calculate CRC?
Reticulocytes (%) x Hct. (%) / 45
A correction made for the presence of prematurely released reticulocytes in circulation. (Can happen with polychromasia) 
Reticulocyte production index (RPI) 
How do you calculate RPI?
Reticulocyte (%) x [Hct.(%)/45] divided by
Maturation time in days
The blood-to-stain ratio does not have to be exactly equal. Explain the reasoning behind this. 
When the patient’s hematocrit (Packed RBCs volume expressed as a percentage) is low, A larger proportion of blood should be added to the stain.
Add a smaller amount of blood to the stain when the patient has an unusually high hematocrit
The time allowed for staining Is not absolutely critical but it should NOT be less than ____ minutes. 
10
What are two things that can cause retics to show pale staining?
-High blood glucose
-Use of heparin as the anticoagulant
It is extremely important that the blood and stain be ________ prior to making each and every smear. 
Mixed well
*retics have a lower specific gravity then mature RBCs
[RBC inclusion stained by new methylene blue]
These will appear as one, sometimes, too, rounded, deep purple staining structures (looks like one big dot) 
Howell-Jolly bodies
[RBC inclusion stained by new methylene blue]
Appear as deposits of several granules closer together (Rather than the “scattered all over” Network-like look of Retics)
-stain a darker blue than retics 
Pappenheimer bodies (aka siderotic granules)
To confirm pappenheimer bodies, what stain should be used? 
An iron stain such as Prussian blue (No other inclusions will show up with this stain, but pappenhimer bodies will)
-These inclusions appear similar to pappenheimer bodies And show up with methylene blue, but disappear with both Wright’s stain and Prussian blue
-they are usually single, or one cluster of just a few particles
Heinz bodies
What are conditions associated with an increased retic count? 
-increased erythropoiesis in response to hemolytic anemia
-Acute and/or chronic bleeding
-post iron deficiency anemia treatment
-Post megaloblastic anemia treatment
What are conditions associated with a decreased retic count?
-decreased erythropoiesis caused by aplastic anemia
-Bone marrow infiltration with fibrotic tissue (myelopfibrosis)
-pernicious anemia
-Sideroblastic anemia
What inclusions can be seen with a Wright’s stain? 
-reticulum (ploychromatophilic, bluish)
-Howell-jolly bodies
-pappenheimer bodies or siderotic granules
Can Heinz bodies be seen on a Wright’s stain?
No
What inclusions show up with new methylene blue stain?
-reticulum
-Howell-jolly bodies
-pappenheimer bodies or siderotic granules
-Heinz bodies
What inclusion shows up with Prussian blue stain?
Pappenheimer bodies
