HEMA 6TH LE

-backup method

-leukocyte count is extremely high or low

-presence of abnormal protein, clumped platelets, antibody elements, abnormal WBC

reasons for using manual WBC count

loss of instrument linearity

why is manual method used when the WBC count is too high or too low?

abnormal protein, clumped platelet, antibody elements, abnormal platelets

examples of samples which cannot be counted using automated instruments for WBC count

number of cells per liter

SI units for WBC count

whole blood w/ EDTA

preferred sample for WBC count

EDTA, heparin, ammonium potassium oxalate

anticoagulants that may be used for WBC count

TRUE

TRUE/FALSE: specimen for WBC count must not have any clots

label with name of diluent and ratio of specimen to diluent

what is done if a diluted specimen is used for WBC count

levy counting chamber/ spencer bright line with improved neubauer ruling

hemacytometer used in WBC count

national bureau of standards

hemacytometers used in WBC count must have the initials of what organization on the chamber

2

number of ruled areas in neubauer hemacytometer

9sqmm

total area of 1 ruled area in the neubauer hemacytometer

0.1mm

depth of neubauer hemacytometer

hemacytometer coverslips are thicker and bigger

difference between normal coverslip and hemacytometer coverslip

-glacial acetic acid

-hydrochloric acid

-turk's solution

diluents used for WBC count

-gentian violet

-distilled water

composition of turk's solution

turk's solution

WBC count diluent that enhances WBC nuclear definition

11 mark

in WBC count the diluting fluid is drawn to what mark

0.5

to obtain a 1:20 dilution, blood is drawn up to what mark

1

to obtain a 1:10 dilution, blood is drawn up to what mark

horizontal position

in specimen preparation for WBC count, when the WBC pipet is filled the pipet is brought to what position

non-absorbent material

what is used to wipe off excess blood from a WBC pipet

absorbs liquid portion of the blood causing erroneous increase

why are absorbent materials such as gauze not used to remove excess blood from WBC pipet

RBC pipet

what is used to collect the sample when the WBC count is too high

WBC pipet

1:20 or 1:10 dilutions are made with what type of pipet

RBC pipet

1:200 or 1:100 dilutions are made with what type of pipet

-failure to mix

-diluent contaminated with blood

-bubbles in the thoma pipet

-blood drawn too far past dilution mark

sources of error in specimen preparation for WBC count

false high results

what are the expected results when blood is drawn too far past the dilution mark in WBC count specimen preparation

distilled water and absolute methanol

what is used to clean the hemacytometer and coverslip for WBC count

microscope lens paper

what is used to dry the hemacytometer after cleaning

scratches the grid and ruin the lines of the hemacytometer

why is gauze not used to dry the hemacytometer after cleaning

leaves fibers on the mixture

why is cotton not used to dry the hemacytometer after cleaning

discard first four drops

what is done after cleaning, and before charging the hemacytometer

clean and recharge the hemacytometer

what is done when bubbles are formed when charging the hemacytometer

3-5 minutes

how long are cells allowed to settle after charging the hemacytometer

4 1sqmm squares

how many squares are counted for WBC count

cells touching the triple lines

when reading the hemacytometer which cells are excluded from the count

unopette

this type of pipet is allowed to touch free flowing blood from a finger puncture or from venous blood

capillary action

blood is sucked in the unopette using what mechanism

FALSE: stops automatically once blood reaches the neck of the pipette

TRUE/FALSE: collection of blood from unopette is stopped by removing the pipet from the blood

glacial acetic acid

diluent inside unopette

1:20

dilution used in a typical unopette

1:100

when WBC is high what dilution is used for the unopette

15

for leukocytes, there should not be a difference of ____ cells between the highest and lowest total number of cells

20

for erythrocytes, there should not be a difference of ____ cells between the highest and lowest total number of cells

-optical principle

-electrical principle

automated methods for WBC count

optical principle

also known as light scattering principle

optical principle

also known as electron optical principle

optical principle

also known as photoelectric principle

optical principle

also known as dark field optical principle

optical principle

in this method blood cells are suspended in electrolytes , pass through a glass flow cell in a single file where they pass the focal point of a light source in a dark field illumination where light scatters

photomultiplier tube

what converts each signal of light to an electrical pulse in optical principle

electrical principle

also known as electronic principle

electrical principle

also known as coulter principle

electrical principle

also known as particle conductivity principle

electrical principle

in this method blood cells are drawn into a glass container with an electrically conductive solution. as blood passes through an aperture an electric current is passed and resistance is measured

TRUE

TRUE/FALSE: blood is a poor conductor of electricity

morning

period when WBC count is lowest

midafternoon

period when WBC count peaks

lower range because of low neutrophil

WBC count of black subjects or persons of african descent

reversed

neutrophil-lymphocyte ratio of blacks subjects or persons of african descent

physical/emotional stimulus

causes of physiologic neutrophilia

TRUE

TRUE/FALSE: physiologic neutrophilia is only transient

high

HIGH/LOW WBC COUNT: appendicitis

high

HIGH/LOW WBC COUNT: leukemia

high

HIGH/LOW WBC COUNT: tonsilitis

high

HIGH/LOW WBC COUNT: diphtheria

high

HIGH/LOW WBC COUNT: meningitis

high

HIGH/LOW WBC COUNT: abscesses

high

HIGH/LOW WBC COUNT: rheumatic fever

high

HIGH/LOW WBC COUNT: erythroblastosis fetalis

high

HIGH/LOW WBC COUNT: newborn

high

HIGH/LOW WBC COUNT: pregnancy

high

HIGH/LOW WBC COUNT: menstruation

high

HIGH/LOW WBC COUNT: pneumonia

high

HIGH/LOW WBC COUNT: small pox

high

HIGH/LOW WBC COUNT: ulcers

high

HIGH/LOW WBC COUNT: uremia

high

HIGH/LOW WBC COUNT: peritonitis

high

HIGH/LOW WBC COUNT: chicken pox

low

HIGH/LOW WBC COUNT: measles

low

HIGH/LOW WBC COUNT: influenza

low

HIGH/LOW WBC COUNT: brucellosis

low

HIGH/LOW WBC COUNT: typhoid fever

low

HIGH/LOW WBC COUNT: agranulocytosis

low

HIGH/LOW WBC COUNT: infectious hepatitis

low

HIGH/LOW WBC COUNT: lupus erythematosus

low

HIGH/LOW WBC COUNT: liver cirrhosis

low

HIGH/LOW WBC COUNT: protein therapy

low

HIGH/LOW WBC COUNT: rheumatoid arthritis

low

HIGH/LOW WBC COUNT: scrub typhus

low

HIGH/LOW WBC COUNT: radiation

low

HIGH/LOW WBC COUNT: sandfly fever

low

HIGH/LOW WBC COUNT: psittacosis

low

HIGH/LOW WBC COUNT: myxedema

low

HIGH/LOW WBC COUNT: paratyphoid

low

HIGH/LOW WBC COUNT: dengue

physiologic neutrophilia

caused by a shift of marginated cells to the circulating pool

pseudoneutrophilia

physiologic neutrophilia is also known as

normal range of WBC count

5000-10000 cumm