Hematology laboratory testing- Automated/Manual

A sample of cerebrospinal fluid is diluted 1:100; the standard 9 squares of a hemocytometer are counted on each side for a total of 18 large squares. Side 1-- 186 nucleated cells counted Side 2-- 184 nucleated cells counted Total nucleated cells = 370 Using the standard hemocytometer formula shown on the right, what is the nucleated cell count per microliter (µL)?

2.06 x 104

In a moderately bloody specimen, 250 cells are counted in 1 primary square. The dilution is 1:100. What is the count/µL?

2.5 x 105

The impedance principle shown in this illustration is best described by the following statement:

Blood cells or other particles are counted and sized based on changes in electrical resistance as they pass between two electrodes

The image on the right is a representative field from a peripheral blood smear. What would you expect to see on the automated blood count?

MCV increased, RDW increased

What does the M:E ratio in a bone marrow evaluation represent?

Myeloid cells to erythroid cells

How many 1 mm x 1 mm squares is the Neubauer hemacytometer counting grid composed of?

Nine per side

When preparing a slide for morphologic examination, what is the reason for adding a drop of albumin to the cerebrospinal fluid (CSF) sample prior to cytocentrifugation?

Preserve the integrity of the cells.

A semen specimen was collected three hours before it was brought to the laboratory for examination. What course of action should be taken?

Report the specimen as compromised on the final report.

You are working in a hematology laboratory and the machine flags an outlier result for a 51-year-old male. The blood was collected in an EDTA tube for a CBC. The hematocrit of the specimen is high at 60%. Which of the following would you do?

Report these results.

Which one of the following hematological determinations is MOST reliable for evaluating bone marrow erythropoietic activity?

Reticulocyte count

A WBC differential count on CSF should be performed using the following technique:

Stained smear of a cytocentrifuged specimen

A hemocytometer is generally used for all of the following, EXCEPT?

Synovial fluid crystal counts

The appropriate magnification for a manual RBC cell count using a hemocytometer is which of the following?

40X (Dry)

A manual white blood cell count was performed by the hematology technologist. The cell counts for each of two sides was 38 and 42 respectively. All nine large squares were counted on each side. The dilution for this kit was pre-measured at 1:10. What should the technologist report as the white cell count?

0.44 x 109/L

Which of the following statements is FALSE?

Nucleated red blood cells can cause a falsely decreased white blood count.

What is the BEST type of microscopy for performing manual platelet counts?

Phase contrast

Which of the following tests would be most affected by microclots in an EDTA tube drawn for a CBC?

Platelet count

The blood is diluted 1:100 and charged on the hemocytometer counting chambers on both sides. If the average platelet count from a counting chamber in one mm2 (one large square) is 68, what is the calculated platelet count?

68,000/mm3

A 1:100 dilution of a patient's peripheral blood was made and a total of 136 platelets were counted in 5 squares of the RBC area of a Neubauer-ruled hemocytometer. What is the Platelet count? Note: The volume correction factor is 50 µL.

680 x 103/µL

A technologist performed a STAT spinal fluid count by pipetting undiluted spinal fluid in a Neubauer Counting Chamber and counting both sides of the chamber (4 large WBC squares on each side). A total of 54 White Cells were counted. How many White Cells would there be per cubic millimeter?

67.5

A 1:10 dilution is made on a CSF sample. Five squares on each side of the hemacytometer are counted for a total of 10 squares and a total of 150 cells are recorded. What is the count per microliter?

1500

A manual white blood cell count was performed by the hematology technologist. The cell counts for both sides were 152 and 164 respectively. All nine large squares were counted on each side. The dilution for this kit was pre-measured at 1:100. What should the technologist report as the white cell count?

17.5 x 109/L

Twenty microliters (20 µL) of blood are diluted with 1.98 mL of diluent. Both sides of the hemocytometer are charged with the diluted sample and the entire ruled area of the center square is counted on both sides. A total of 356 platelets are counted (combined total of the two large squares). What is the platelet count per liter?

178 x 109/L

Given the following information, what is the CORRECTED white count? Initial White count = 35,000/µL92 nucleated red blood cells are noted per 100 WBC's counted on the manual differential

18,229/µL

If the spinal fluid is slightly hazy, what is the best dilution?

1:10

A dilution commonly used for a routine sperm count is:

1:20

What is the optimal time to begin initial microscopic examination of a semen specimen, assuming liquefaction is complete?

30 minutes

Two CSF specimens were sent to the Lab with the following results:Tube #1 = 11,200 rbc/µLTube #2 = 300 rbc/µLThe results on these CSF specimens are indicative of:

A traumatic tap

A complete blood count is performed. The white blood cell count is elevated and a manual differential is required. The technologist evaluates the red blood cell morphology and finds it "Normal." Which of the following histograms would represent a normal red blood cell morphology?

B

Cell counts on CSF specimens should be performed within what time frame following collection of the CSF sample?

Within one hour

A cloudy CSF sample has a white count of over 1,000 WBC/µL. The large number of these cells seen in the cytocentrifuged smear in this illustration is suggestive of:

Bacterial infection

All of the following tests are included in a complete blood count (CBC), EXCEPT?

Blood culture

A manual white blood cell count was performed by the hematology technologist. The cell counts for both sides were 99 and 164 respectively. All nine large squares were counted on each side. The dilution for this kit was pre-measured at 1:100. What should the technologist report as the white cell count?

Cannot report

What would be the logical first step to obtain correct values when the following results were obtained on an electronic particle counter in hematology for an alcoholic patient? WBC 6,500/cu. mmMCV 90.1 fLRBC 4,550,000/cu. mmMCH 39.6 pgHGB 18.0 g/dLMCHC 43.4%HCT 41.5%

Check and correct for lipemia

A 40-year-old man patient presents with non-specific physical complaints which include abdominal pain. Based on symptoms and family history the physician suspects Hereditary Hemochromatosis. Which of the following laboratory tests would be the LEAST diagnostic?

Complete blood count

Which of the following tests should be collected in a EDTA (lavender top) tube?

Complete blood count (CBC)

A cell count is ordered on a CSF sample that is bloody. Which of the following procedures would improve count accuracy?

Dilute the sample to minimize the number of red blood cells in the squares being counted.

Charcot-Leyden crystals in stool may be associated with an immune response and are thought to be the breakdown products of:

Eosinophils

Classic automated blood cell counters are based on which of the following technologies

Impedance principle

The image is a Wright-Giemsa stained smear (1000x) of cerebrospinal fluid (CSF). The arrows point to cells that may indicate which of the following conditions?

Leukemia with CNS involvement

A technologist decides to make a 1:20 dilution of cerebrospinal fluid (CSF) after briefly evaluating a portion of the sample microscopically. After making the dilution and charging the chambers, the number of cells that are observed in each of the large squares of the hemocytometer is >100. What should the technologist do to obtain the most accurate count?

Make a larger dilution.

Which of these descriptions correlates best with the red cell distribution curve shown?

Normal red cell distribution

The site most frequently used to collect bone marrow samples from adults is:

Posterior iliac crest

The image is a Wright-Giemsa stained smear (1000x) of cerebrospinal fluid (CSF). What is the identification of the cells that are indicated by the arrows?

Presumptive malignant cells

Upon centrifugation, a cerebrospinal fluid (CSF) sample supernatant exhibited xanthochromia. The image is a Wright-Giemsa stained smear that was made from that CSF sample. What condition is probably related to these macroscopic and microscopic findings?

Previous subarachnoid hemorrhage

An automated hematology counter flagged the white blood cell count. Upon review of the peripheral blood smear, the technologist viewed many cells that appeared similar to those in this image. What should the technologist report?

Reactive/atypical lymphocyte

What would be the next step when an EDTA specimen had an automated platelet count of 61,000/mm3 and the platelets were surrounding the neutrophils on the differential?

Recollect a specimen for a platelet count without using EDTA

What is a corrective action that can be used to obtain a valid platelet count from a patient specimen that exhibits platelet satellitism on the manual differential?

Recollect the blood specimen in a blue top tube containing sodium citrate

Which of the following formulas would you use to calculate absolute cell counts?

Total count X % of cells counted

Cerebrospinal fluid (CSF) specimens are usually collected by lumbar puncture and placed in numbered tubes starting with the first tube collected. If four tubes are collected, which tube would be used for a cell count and differential?

Tube #3

All of the following can cause erroneous automated platelet counts EXCEPT?

WBC fragmentation

You are analyzing a patient sample in the hematology laboratory when the instrument you use for automatic CBC flags your specimen for having a low platelet count. Upon performing a visual differential of the slide, you notice that there are indeed very few platelets on the slide. You also notice numerous, fragmented red blood cells. Which of the following choices could be associated with the low platelet count and fragmented red blood cells found in this case?

hrombotic Thrombocytopenic Purpura (TTP)

When three tubes of cerebrospinal fluid are received in the laboratory they should be distributed to the various laboratory sections as follows:

#1 Chemistry, #2 Microbiology, #3 Hematology

How many large hemacytometer squares contain a total volume of 1 µL (microliter) of fluid?

10

A sample of cerebrospinal fluid is diluted 1:100; the standard 9 squares of a hemocytometer were counted on each side for a total of 18 large squares. Side 1- 186 cells counted Side 2- 184 cells counted total cells = 370 What is the cell count per microliter?

2.06 x 104

A 1:20 dilution is made for a manual WBC count. The four corner squares on both sides of a hemocytometer are counted. A TOTAL of 100 cells are counted (eight total squares). What is the white blood cell count in terms of a liter?

2.5 x 109/L

What should be added to the cytocentrifuge chamber when preparing slides on serous fluids to aid in adhesion of cells to the slide and preserve cellular morphology?

22% Albumin

A manual WBC count was performed. A TOTAL of 72 cells were counted in 4 large mm squares of a Neubauer-ruled hemacytometer. A 1:20 dilution was used. What is the calculated WBC count?

3.6 x 103/µL

Which of the following represents the White Blood Cell (WBC) count reference range for adults?

4.4 - 11.0 x 109/L

Pleural fluid was sent to the laboratory for a WBC count. The specimen was NOT diluted.WBCs in 5 large squares were counted in each side of the hemacytometer.The number of WBCs counted were as follows:Top counting chamber: 35 cells total (in 5 large squares)Bottom counting chamber: 33 cells total (in 5 large squares)Based on the information provided above, calculate the total WBC count.

68 cells/mm3

When performing a manual white blood cell count, 236 cells were counted on side number one of the hemacytometer, 224 cells on side number two. A 1/20 dilution of 1% HC1 was used and the area counted on each side was 4 sq. mm. Twenty-five nucleated red blood cells in the differential were observed per 100 white blood cells. What is the CORRECT WBC/µL?

9,200

What is the corrected white blood cell count if the WBC is 14,460, and there were 47 nucleated red blood cells per 100 white blood cells noted on the differential count?

9,837

A white blood cell (WBC) count is performed on a blood specimen from a newborn using a hematology analyzer that does not have the capability to detect and quantify nucleated red blood cells (NRBCs). The WBC count that is reported by the analyzer is 28.2 x 109/L and it is flagged for a manual differential. Upon review of the blood film, more than 6 nucleated cells that resemble the cells shown in the image were identified in the 100 WBC differential. What action should be taken?

Count the number of cells that resemble the cells in this image (per 100 WBCs) and compute for the corrected WBC count using the formula, Total WBCs x100 / 100+ number of NRBCs

Which of the following is the recommended method for preparing a cerebrospinal fluid (CSF) sample for a differential count?

Cytocentrifugation

A manual platelet count was performed using a Neubauer hemacytometer. The total platelet count was 356 x 103/µL. A platelet estimate was then performed on the peripheral blood smear. Ten fields were counted and yielded the following results: 17, 16, 15, 20, 19, 17, 19, 16, 20, 18. The platelet estimation factor for the microscope used was 20,000. What is the next logical step?

Report the manual platelet count since it correlates well with the platelet estimate

In reference to semen analysis microscopic examination, differentiation and enumeration of "round cells" which are often present in semen count are refered as:

White blood cells (WBCs)