ASCP MLT Cert exam
Antenatal Rh Immune Globulin (RhIG) is typically given at how many weeks gestation?
28 weeks
What transferrin saturation level would be indicative to investigate further for hereditary hemochromatosis (HH)?
45% and up below 45% is normal
A platelet component prepared from a unit of whole blood (random donor platelet) must contain at least how many platelets?
5.5 x 1010 platelets/unit
Which of the following would be considered a normal value for a glucose level in cerebrospinal fluid?
60mg/dl
What is a hemiacetal?
A compound with both a carbonyl and alcohol group.
Which of the following is/are considered an accrediting agency(ies) for quality and safety in the blood industry?
AABB
The direct antiglobulin test (DAT) is most unreliable when diagnosing hemolytic disease of the fetus and newborn due to which blood group system?
ABO
All of the following are currently used to diagnose acute coronary syndrome and/or acute myocardial infarction, EXCEPT?
BNP
For the diagnosis of Systemic Lupus Erythematosus (SLE) which of the following test principles provides the highest specificity? The correct answer is highlighted below
ELISA tests are available allowing us to determine the presence of anti-Smith, anti-double-stranded DNA, anti-histone, anti-SS-A, anti-SS-B, anti-Rnp or anti-Scl-70 which provide greater specificity for a diagnosis of SLE.
Isoenzymes of alkaline phosphatase occur in:
Kidney, bone, intestines, liver
Identify a characteristic of an organ-non specific disorder that distinguishes it from an organ specific disorder.
Lesions caused by deposition of antigen-antibody immune complexes
Based on the results of in-vitro susceptibility testing, patients with septicemia from each of the bacterial species listed below can potentially be treated with vancomycin EXCEPT:
Leuconostoc species
Which subset of effector lymphocytes is predominantly responsible for regulation of antibody production?
TH2
How many milliliters of 3N solution can be made from 50g of CaCl2?
To determine how many mL of 3N solution can be made from 50 g of CaCl2, you would need to determine the molecular and eq weight of CaCl2 then use the following equation to determine how many mL are needed to make the desired concentration: g = (eq wt)(N)(volume in L). mol wt of CaCl2 = 40 + (35.5 X 2) mol wt of CaCl2 = 40 + 71 mol wt of CaCl2 = 111 eq wt of CaCl2 = mol wt / pos valence eq wt of CaCl2 = 111 / 2 eq wt of CaCl2 = 55.5 g = (eq wt)(N)(volume in L) 50g = (55.5)(3N)(XL) 50g / 166.5 = XL X = 0.3L = 300 mL
Which modified PCR technique or other method of amplification is used to detect Mycobacterium tuberculosis?
Transcription-Mediated Amplification
This parasite, found in striated muscle, is responsible for which of the following conditions? (worm in spiral)
Trichinosis The organism pictured is Trichinella spiralis. This organism is an intestinal-tissue nematode whose larvae encyst by coiling in muscle tissue. Humans are an accidental host that becomes infected when encysted larvae are ingested through poorly cooked pork.
Following the treatment of an IgG molecule with papain, which of the following will remain?
Two Fab fragments each with a light chain and a partial heavy chain attached with a disulfide bond
Which of the following steps must be followed to prepare a platelet concentrate?
Whole blood centrifuged at low speed - plasma separated then centrifuged at high speed
The Philadelphia chromosome is consistently associated with which of the following blood disorders?
CML
Where does most cerebrospinal fluid originate?
Choroid plexus
A patient has a history of repeated spontaneous abortion. Coagulation studies reveal an elevated APTT, normal PT, normal platelet function, and normal thrombin time. Schistocytes were seen on the peripheral blood smear.
Platelet neutralization tests are one of the confirmatory tests that can be used to determine if a patient has a circulating lupus antibody, or lupus anticoagulant. The principle in this test involves the use of a freeze-thawed platelet suspension that, when mixed with the patient plasma, will neutralize the anti-phospholipid antibodies (lupus anticoagulant) present and allow for a corrected APTT result upon re-testing. A Factor VIII assay would be abnormal due to the interference of the lupus anticoagulant with the phospholipid in the APTT test that is used to measure Factor VIII activity. Mixing studies are useful as screening tests for lupus anticoagulant and phospholipid antibodies. Mixing studies with factor deficient plasmas and the APTT test would all be abnormal due to the interference of the lupus anticoagulant with the phospholipid in the APTT test that is used to perform the mixing studies. A mixing study using the patient's plasma incubated 1:1 with normal plasma would also be abnormal (uncorrected). The antinuclear antibody test is a screening test for autoimmune diseases such as systemic lupus erythematosus (SLE). Although some patients with SLE may have a lupus anticoagulant, not all patients with lupus anticoagulant have SLE.
Which of the folloing is the prodrug of phenobarbital?
Primidone
After frozen RBC's have been thawed and washed, they must be used within how many hours?
24hrs
An increased serum level of which of the following analytes is MOST commonly associated with decreased glomerular filtration?
Creatinine
A key laboratory characteristic by which Mycobacterium bovis can be separated from Mycobacterium tuberculosis is:
Growth inhibition by thiopine-2-carboxylic acid hydrazide (T2H)
The antigen marker most closely associated with transmission of HBV infections is:
HBeAg
Recovered from hep B
HBsAg (neg), Anti-HBc(pos) anti-HBs (pos) is the profile of a patient who has recovered from an HBV infection.
Immune to Hep B
HBsAg (neg), Anti-HBc(pos) anti-HBs (pos) is the profile of a patient who is immune to HBV because of natural infection.
Chronic hep B
HBsAg (pos), Anti-HBc(pos,) anti-HBs (neg) is the likely profile of a patient with chronic hepatitis B.
The gel electrophoresis pattern for hemoglobin S (HbS) shows which of the following migration patterns?
HbS migrates with HbD in alkaline and alone in acid electrophoresis.
How long can the following blood products be stored: 1. CPDA-1 2. CPD/CP2D 3. Irradiated RBCs 4. RBCs with additive solutions
1. The addition of adenine to the anticoagulant-preservative solution allows the red blood cell unit to be stored for up to 35 days rather than 21 days. 2. CPD or CP2D blood can be stored for up to 21 days. 3. Irradiated red blood cells expire either after 28 days from irradiation or on the original expiration date, based on which date occurs first. 4. Additive solutions increase the shelf life of donated blood products to 42 days.
What is the minimum hemoglobin concentration required for autologous blood donation?
10 g/dl
Over budget formula
((Actual Expenses - Budgeted Amount)/Budgeted Amount) x 100
A patient admitted to the hospital for ongoing fever produces the following laboratory results: RBC count: 3.56 x 1012/L WBC count: 57.5 x 109/L Platelet count: 375,000/uL Differential count: 3 blasts, 10 myelocytes, 6 metamyelocytes, 12 bands, 64 segs, 4 lymphocytes, and 1 monocyte LAP score = 155. Which of the following conditions correlates closely with this patient's results?
A high white blood cell count, usually 50-100 x 109/L with a left shift is a common finding in leukemoid reactions. In addition, a key feature of a leukemoid reaction is a high LAP score.
A typical Bronchoalveolar lavage differential contains all the cells EXCEPT:
A typical BAL would NOT include mesothelial cells as they are lining cells for serous fluids. A typical BAL would include ciliated lining cells, macrophages, and lymphocytes.
The colonies shown in the blood (BAP) agar (upper) and MacConkey (MAC) agar (lower) biplate are a 24 hour growth from an aerobic blood culture bottle that became positive at 12 hours after inoculation. The appearance of the colonies on MAC agar rules out the following bacterial species:
Although Pseudomonas aeruginosa may produce mucoid colonies on MAC agar, it does not ferment lactose, which is evident from the pink pigmentation of the colonies.
Ethanol and osmolality
An elevated ethanol concentration in the sample would result in a higher measured osmolality than the calculated osmolality. The salicylate, acetaminophen, and electrolyte concentrations are at levels that would not cause a significant difference between the measured and calculated osmolality. There is a significant difference between the measured and calculated osmolality for this specimen.
A stool culture showing increased number of fecal leukocytes would correlate with an infection of which of the following species?
An increased number of fecal leukocytes correlates with an invasive gastrointestinal infection. Organisms that can show this include Shigella, Salmonella, Campylobacter, Yersinia, and Enteroinvasive Escherichia coli (EIEC).
Which of the following markers would you expect to find in the serum of a patient who has recently recovered from Hepatitis B infection?
Anti-HBs
Fecal urobilinogen level may be markedly decreased because of:
Biliary obstruction
All of the following statements are characteristic of the role of C-reactive protein (CRP) except?
Binds with factor H to initiate alternate complement pathway.
What crystals are found in acidic urine?
Crystals and sediment found in acid urine include cystine, leucine, calcium oxalate, sodium urate, sulfonamide, tyrosine, uric acid, and amorphous urates
All outpatient tests are reimbursed according to a group of code numbers which are called:
Current Procedural Terminology (CPT) codes
Which of the following is the best media for recovery and presumptive identification of Clostridioides (formerly Clostridium) difficile in suspected cases of pseudomembraneous colitis?
Cycloserine-cefoxitin fructose agar (CCFA) is used to recover Clostridioides (formerly Clostridium) difficle from stool specimens. This media is selective and differential for the recovery and presumptive identification of the organism. C. difficle produces yellow ground-glass colonies and the agar turns from pink to yellow due to the fermentation of fructose. The acid produced changes neutral red, the pH indicator, from red to yellow. While other organisms may grow on the media, they are smaller and do not resemble the characteristic colonies. C. difficle colonies also have the odor of a horse barn and fluoresce chartreuse under UV light. All of the above allow for the presumptive identification of C. difficle on this media.
What are Howell-Jolly bodies composed of?
DNA
The Lutheran b antigen (Lub) is a high incidence antigen. A patient has developed an anti-Lub. All of the screening cells and antibody identification panel cells are positive at AHG. What can be used in testing so that the blood bank can determine if there are other clinically significant antibodies present in this patient?
DTT
In patients with suspected primary hypothyroidism associated with Hashimoto's thyroiditis, one would expect the following laboratory test results:T4 ___? TSH ___? TRH stimulation ___?
Decreased, increased, increased
Abnormal platelet function seen in patients with Bernard-Soulier Syndrome is caused by which of the following platelet components?
Defective glycoprotein Ib/IX
Serological detection of the Vi antigen aids in identification of:
Detection of somatic (O), flagellar (H), and capsular (K) antigens are used in serologic grouping of Enterobacteriaceae. Many members of this family possess somatic and flagellar antigens, whereas non-motile species lack flagellar antigen. From the organism choices, Salmonella Typhi has the capsular Vi (virulence) antigen, which may mask the presence of the O antigen.
When operating a centrifuge, what happens if the centrifuge is not properly balanced?
Exposure to biohazardous agents
Conditions that produce elevated CSF protein levels include all of the following EXCEPT:
Fluid leak
Leuconostoc species are streptococcus-like bacteria used in the dairy and pickling industries that have recently caused opportunistic infections in humans. The need to make the laboratory identification is compounded because these bacteria are intrinsically resistant to vancomycin. Which characteristic is most helpful in separating Leuconostoc species from other streptococcus-like organisms?
Gas from glucose in MRS broth Leuconostoc species may be misidentified as Enterococcus, alpha-hemolytic streptococci, Pediococcus, Lactococcus, or lactobacilli (Facklam R, Elliott JA: Clin Microbiol Rev; 1995 Oct; 8(4):479-95). The detection of gas from glucose in Mann, Rogosa and Sharpe (MRS) broth (available from Difco Laboratories) overlaid with petrolatum is the one characteristics that differentiates Leuconostoc species from the other streptococcal-like organisms. All of the other characteristics listed in this exercise are either variable for Leuconostoc species or are shared by other streptococcal-like organisms and therefore are not discriminatory tests.
Acute-phase proteins generally fall into which category?
Glycoproteins
In which developmental stage do red blood cells begin forming hemoglobin in amounts large enough to be visualized on a Wright-stained bone marrow aspirate smear?
Hemoglobin synthesis is detectable in the basophilic normoblast, but the formation of large amounts of hemoglobin begins in the polychromatic (polychromatophilic) normoblast. On a Wright-stained bone marrow aspirate smear, the cytoplasm of the polychromatic normoblast is murky gray-blue, which is due to a mixture of pink (from hemoglobin) and blue (from RNA). The cytoplasm of the basophilic normoblast is a deep, rich blue; any amount of hemoglobin produced during this stage is masked by the presence of large amounts of ribosomes and RNA.
Which antibody class is best described with that characteristic that it is the only one capable of residing in mucosal linings?
IgA
Coombs check cells are coated with
IgG antibodies
A 45-year-old African American female has been diagnosed and treated for type 2 diabetes for the past five years. She maintains good control of her blood glucose with medication but does not exercise and has gained 12 pounds over the past year. At her next appointment, her physician orders hs-CRP along with blood assays to monitor her diabetes. Laboratory Result: hs-CRP 2.8 mg/L
In 2003 the American Heart Association and the CDC published a set of clinical guidelines for the use of hs-CPR as a marker for cardiovascular disease (CVD) risk. hs-CRP <1 mg/L represents a low risk of CVD hs-CRP 1.0-3.0 mg/L represents a moderate risk of CVD hs-CRP >3.0 represents a high risk of CVD In our case, a hs-CRP of 2.8 mg/L indicates a moderate risk of CVD (1.0-3.0 mg/L).
This antinuclear antibody (ANA) pattern is characterized by granular staining in the nuclei of the interphase cells (a). There is also an absence of staining in the chromosomal area of the metaphase mitotic cells (b). The slide is viewed using fluorescent microscopy. Which pattern is this?
In order for the ANA to be positive there must be a clearly discernible pattern in the nuclei of the interphase cells. Metaphase mitotic cells are used to assist in identification of the ANA pattern. The image shown displays the features of a speckled ANA pattern: granular/speckled staining in the nuclei of the interphase cells (a) and absence of staining in the chromosomal area of the metaphase mitotic cells (b). The nucleoli do not stain; thus, the pattern is not nucleolar. A homogeneous pattern would show uniform staining of the nuclei in the interphase cells and presence of staining in the chromatin of the dividing cells. The centromere pattern is characterized by many discrete speckles in both the nuclei of interphase cells and the chromatin of dividing cells.
Which of the following D variants has the best likelihood to receive D-positive RBCs without any adverse effects?
Individuals with C in Trans to RHD possess complete D antigen structures. The allele that carries C is in trans (or opposite position) from the allele carrying RHD. As a result, the position of the C antigen in relationship to the D antigen interferes with the expression of the D antigen. This can be a weakened expression of D antigen; however, D antigen is still present. These patients can receive D-positive RBCs without the implication of an Rh-mediated transfusion reaction.
Le(a-b+)
Le Se
Le(a+b-)
Le sese
In theory, how difficult is it to find a compatible blood unit and to identify the antibody in a patient with an antibody to a low-frequency antigen, such as Kpa or Jsa?
Low-frequency antigens are not often found in the population and maybe as rare as <1% of the population. Because of this, it is not difficult to find compatible units for a patient with the corresponding antibody since few people would possess the antigen. However, identifying the antibody would be difficult since the corresponding antigen would not be found on many reagent red cells, making the Rule of Three difficult to accomplish.
Which antibody is associated with Mycoplasma pneumoniae infection and cold hemagglutinin disease?
M. pneumoniae carries an antigen that resembles the I antigen. Thus, when the body develops an immune response against this antigen, the antibodies may cross-react with the I antigen on red blood cells. Anti-I is also associated with cold hemagglutinin disease.
Matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) is used for identification of aerobic bacterial isolates on a urine culture bench. Upon placing the target into the MALDI-TOF instrument, no peaks were found on any target spots, including the quality control. What caused this issue?
Matrix solution is required for the MALDI-TOF to properly identify the organisms, by extracting proteins from the organisms on the target. Once the proteins are extracted with matrix, they each generate a distinct signal (peak) and then spectrum. This spectrum is compared to know spectra in a database to identify the organisms. Since there were no peaks found on the target, this points to the fact that no proteins were extracted to make those peaks. Also, since all the target spots did not work, including the quality control, this points to a procedural error that occurred with all the target wells. If there was no quality control organism applied to the target, just the quality control target wells would have no peaks. At least some of the other target wells should have peaks found if matrix solution is added correctly. Since all the target wells had no peaks, the problems stem from more than the quality control. Targets are cleaned after use and if not cleaned properly, identifications may show as mixed or may not match with colony morphology if residual organism is left on the target. Residual organisms from improper cleaning would show as peaks, just incorrect peaks. If the quality control organism has deteriorated, just the quality control target wells would have an issue of no peaks or no identification. With all target wells showing no peaks, the matrix was not added to extract the proteins.
Tumor markers are especially valuable when used to:
Monitor response to cancer therapy
Which one of the following blood group antigens is not expressed, or only weakly expressed on cord blood cells?
Newborns are phenotypically Le(a-b-). Lewis antigens are soluble and appear on a variety of cells in the months following birth. ABO antigens are present on cord cells, but in a reduced amount as compared to adult cells. K and M antigens are well developed on cord cells.
In serum protein electrophoresis all of the following proteins reside in the band closest to the anodal end EXCEPT:
Of the options listed haptoglobin would not appear in the albumin band. Haptoglobin, a protein that binds free plasma hemoglobin, would appear in the alpha-2-globulin band.Upon separation of proteins in serum protein electrophoresis, five bands will appear. The albumin band is closest to the anodal end. The proteins included in the albumin band include albumin, transthyretin (also referred to as prealbumin), and retinol-binding protein (RBP).
Of the following blood group antibodies, which has been most frequently associated with severe cases of hemolytic disease of the fetus and newborn (HDFN)?
Of those listed, anti-K is most frequently associated with severe forms of HDFN. Anti-K is considered the most clinically significant antibody outside of the Rh system. Kell antigens are found on both immature and mature red blood cells leading to destruction of precursor and circulating red blood cells.
Which of the following drugs is listed as an anti-convulsants?
Phenobarbital
Which of the following terms could be used to describe an analyzer that can test specimens out of sequence?
Random access
Which one of these test systems can be used to evaluate the adequacy of fibrinogen in heparinized patients?
Reptilase Time
An Rh negative mother has just given birth to an Rh positive baby. Her physician suspects that she has experienced a fetal-maternal hemmorhage since her rosette test was positive. Upon performing the Kleihauer-Betke stain procedure, the percentage of fetal cells is found to be 0.85%. The mother's total blood volume is 4,565 mL. What dose of Rh Immune Globulin (RhIG or RhoGam) should be administered to the mother?
Rh immune globulin, also known as RhIG or RhoGam, is used to help prevent an Rh negative mother from becoming sensitized to the D antigen from an Rh positive baby. To do this, vials of Rh Ig must be administered correctly. One full dose vial (300µg or equivalent) per 30 ml of D positive whole blood (15 ml D positive packed RBCs). To calculate how many vials are needed, the following formula can be employed: KB% x blood volume = volume of baby blood In this case: 0.85% (0.0085) x 4,565mL= 38.8 mL baby blood in maternal circulation 38.8mL / 30 mL per Rh Ig vial = 1.29 vials 1.29 vials can be rounded to 1 vial. In addition, an extra vial is always added. Therefore, 2 vials is the correct answer.
The type of sporulation of the dematiaceous mold that is illustrated in this photomicrograph is called:
Rhinocladiella
Which of the following would be considered most significant as it relates to serological testing:
Rise in antibody titers is diagnostic
After experiencing crippling pain in her chest, Elizabeth's mother rushes her to the Emergency Room. After a complete blood count and differential are ordered, the hematology technologist views many peripheral cells similar in appearance to those found in the image below. Which condition is most likely present?
Sickle Cell Anemia
Although some strains may possess K antigen, which member of Enterobacteriaceae is classified serologically by O antigen, because it lacks H antigen?
Somatic (O), flagellar (H), and capsular (K) antigens are used in serologic grouping of Enterobacteriaceae. Many members of this family possess somatic and flagellar antigens, whereas non-motile species lack flagellar antigen. From the organisms listed, Shigella species is the correct answer because Shigella is non-motile (lacking flagella). The other members of Enterobacteriaceae listed are motile and possess H antigen.
While many isolates of this organism remain susceptible to penicillin, resistance is increasing in some areas due to the organism's altered penicillin binding proteins. In such cases, the recommended treatment is erythromycin or chloramphenicol. Which of the following organisms does this desribe?
Streptococcus pneumoniae is the correct answer. Penicillin resistance among S. pneumoniae isolates has increased over the past decades. The resistance is due to the altered penicillin binding proteins of the particular isolate. In cases where penicillin resistance is detected, erythromycin or chloramphenicol usually provides successful treatment.
Illustrated in the upper image is the anterior portion of a nematode filariform larva with a short buccal cavity. The ovum illustrated in the lower image is also part of the life cycle of this nematode. With these observations, what presumptive identification can be made from the parasite species listed below?
Strongyloides stercoralis is the correct response. The Strongyloides ovum, as illustrated in lower image, does not rule out one of the Hookworm species that have similar appearing ova. However, the short buccal cavity, as illustrated in this upper image, is distinctive for Strongyloides.
Moraxella catarrhalis
The big clues in the question were the Gram negative cocci (diplococci) and no growth on MacConkey that ruled out the other organisms in this list. All of the other organisms are Gram negative bacilli or cocobacilli but do grow on MacConkey agar. The colonies growing on chocolate agar are small, initially pinpoint in size after 24 hours incubation, and non-pigmented. Growth on Thayer Martin media is scant or absent, ruling out pathogenic Neisseria species. Small, Gram negative cocci are observed in Gram stains. Cytochrome oxidase, nitrate reduction, and catalase reactions are positive. Acid is not produced from carbohydrates (asaccharolytic). M. catarrhalis is commonly recovered from upper respiratory and ear specimens obtained from patients with otitis media and sinusitis. To confirm the identification, butyrate esterase testing can be performed, which is positive for M. catarrhalis.
Identify the cell in this image:
The cell in this image is a promyelocyte. The promyelocyte varies in size from 15 to 21 µm with a large nucleus. The nucleus to cytoplasmic (N:C) ratio is high (3:1). Several nucleoli may be present in the nucleus, which stains purple to dark blue. The cytoplasm is basophilic and similar to that of a myeloblast but contains prominent, reddish-purple primary granules (usually more than 20). These primary granules are also call azurophilic granules or nonspecific granules. Myeloblasts vary in size from 14 to 20 µm and have a high N:C ratio (4:1). Myeloblasts sometimes contain primary granules, but if they do, there are less than 20. Blasts without granules are referred to as Type I blasts while blasts with up to 20 primary granules are called Type II blasts. Nucleoli are prominent in the nucleus. Myelocytes vary in size from 12 to 18 µm with a N:C ratio of 2:1. Nucleoli are usually not visible and primary granules have either almost disappeared or are not visible. Secondary granules are becoming predominant in the myelocyte as it matures. Metamyelocytes range in size from 10 to 15 µm. The nucleus has a kidney-bean shape (indentation has begun) with no visible nucleoli. The indentation is said to be less than 50% of the diameter of a hypothetical round nucleus. There are many secondary granules in this stage of development.
The cells shown in the image to the right are:
The cells depicted in this image are transitional epithelial cells. These cells originate from the renal pelvis, ureters, bladder, and/or urethra and they are usually round or polygonal. They are smaller and smoother in outline than squamous cells, but larger than a white blood cell (WBC).
A laboratory information system (LIS) consists of:
The computer hardware and software which provide the means to manage data used in laboratory operations.
What is the half-life of immunosuppressive drugs cyclosporine and tacrolimus?
The correct answer is 10-12 hours for both cyclosporine and tacrolimus drugs.
What function in the body does GGT have?
The correct answer is the transfer of gamma-glutamyl peptides to amino acids, water and other peptides. GGT does not transfer amino acids to other compounds (think AST and ALT) or water as it is specific for gamma-glutamyl. Cholesterols do not have gamma-glutamyl peptides attached to them.
The diffuse erythroderma and edema of the hand shown in the upper photograph is of a 24 year old female with fever, headache and hypotension. The blood agar plate shown in the lower photograph was inoculated with purulent material aspirated from a vertebral disk abscess. The most likely condition is:
The diffuse redness and subcutaneous swelling of the hand seen in the upper photograph is a hypersensitivity reaction to a foreign protein or toxin. The brief case history indicates that the patient is in the early stages of febrile shock. The blood agar plate shows large, opaque, white, beta hemolytic colonies most consistent with Staphylococcus species. These associations make toxic shock syndrome as the most likely condition, with the erythroderma secondary to reaction to the TSS-toxin-1.
The peripheral blood smear represented by the image on the right was submitted for hematologic review. The identification of the RBC inclusions shown are most likely identified as:
The intended response is basophilic stippling. Basophilic stippling represents particulate remains of an abnormal hemoglobin formed by defective heme synthesis. These particles are diffusely scattered and stained blue (see erythrocyte at tip of blue arrow), representing precipitates of ribosomes and polyribosomes (RNA). They are released in anemic conditions by the red cell proliferative response. A courser stippling may be present in thalassemia and lead poisoning.
The selectivity of an ion-selective electrode is determined by the:
The membranes of ion-selective electrodes will determine which analyte is measured by the electrode. These membranes are typically made out of glass, crystalline, or polymeric materials. Their chemical composition is designed to select the desired ion.
A physician calls the lab wanting to order a Hepatitis A IgG test but cannot find the code. What do you tell the physician?
There are no IgG-only tests for Hepatitis A, only a total with/without reflex to IgM The correct answer is There are no IgG-only tests for Hepatitis A, only a total with/without reflex to IgM. This is because an IgG test only tests for exposure to the virus and cannot determine current or past infection. If a physician is looking for current infection, an IgM test should be ordered. Normally, a total Hep A antibody test will be performed and is positive, will reflex to IgM to look specifically for current infection. Testing does not differentiate specifically IgG from IgM. There are no antigens tests for Hepatitis A, specific antibodies to parts of the virus like with testing for Hepatitis B, and it does not depend on where the patient is coming back from. There are, however, stool antigen test for Hepatitis A as the viral particles are shed in the feces but is not found once liver enzymes reach their peak.
A patient has anemia with an elevated mean corpuscular volume (MCV) of 106 fL (reference range 80-100 fL). All of the following could be likely causes EXCEPT:
Vitamin B12 deficiency
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?
WBC count = (dilution ratio x # of cells counted x 10) / (# mm2 area counted) Then: WBC count = (20 x 100 x 10) / (8) = 2500 WBC/mm3 (or 2500 WBC/µL or 2.5 x 103 WBC/µL) To find the WBC count per liter, multiply the WBC count/µL by the number of µL/L (there are 106 µL/L) So: (2.5 x 103 WBC/µL) x (106 µL/L) = 2.5 x 109 WBC/L
Nephelometry involves the measurement of:
When light strikes a particle in a solution, it can be absorbed, transmitted, reflected, or scattered. Nephelometry is used to measure the light scattered by particles in a solution. It is useful for measuring protein levels in fluids, and antigen-antibody complexes.
E. coli
a lactose fermenter, is used as the control organism to visualize the acid slant/acid deep reaction (yellow/yellow).
S. flexneri
a non-lactose fermenter to visualize the alkaline slant/acid deep reaction (yellow/red)
P. aeruginosa
a nonfermenter, so it cannot produce acid from glucose in a fermentative medium. Therefore, there is no change in the KIA tube and both the slant and the deep remain alkaline (red/red).
Hybridization is also called
annealing
Burkholderia cepacia
colonies are relatively small, entire, convex and smooth, with gray yellow pigmentation. Colonies grow on MacConkey agar and are without pigment characteristic of a non-fermenter. The oxidase and catalase reactions are positive; however, nitrate reduction is negative. Acid is produced oxidatively from most carbohydrates. B. cepacia is often recovered from sputum samples of patients with cystic fibrosis.
Acinetobacter baumannii
colonies growing on blood agar are relatively large, white, entire, convex and opaque. Entire, smooth, slightly wrinkled colonies with light pink pigmentation are produced on MacConkey agar. Gram negative coccobacilli are also observed in Gram stains. Oxidase and catalase reactions are negative. A. baumannii is saccharolytic while A. lwoffii is asaccharolytic.
Alcaligenes faecalis
colonies on blood agar are grey pigmented and spreading, with light pigment extending into the adjacent agar. Small, plump, Gram negative coccobacilli are seen on Gram stain. A. faecalis does grow well on MacConkey agar. Acid is not produced from carbohydrates and cytochrome oxidase and catalase reactions are positive. Distinctive is the denitrification of nitrates with the production of gas.
Duffy antigens are
denatured by enzymes
Kidd antigens are
enhanced by enzymes
Which marker is most useful for the detection of gestational trophoblastic disease?
hCG (human chorionic gonadotropin)
Le(a-b-)
lele sese
In a normal CSF the protein concentration as compared to that in the plasma is generally:
less than 1%
HHMM is LD 3 and found in
lung, lymphocytes, spleen and pancreas
A standard blood donation of 450-500 mL requires a minimum anticoagulant-preservative solution volume of:
minimum: 63 ml maximum: 70 ml
All of the following are directly involved in the production of semen EXCEPT? The correct answer is highlighted below
pituitary gland
A false-positive result can be observed in a rheumatoid factor latex agglutination procedure reaction due to:
poor specimen quality
The primary site of reabsorption of glomerular filtrate is the
proximal convoluted tube
What is the most frequent genotype among Rho (D) negative persons?
rr The most frequent genotype among Rh-negative individuals is rr. The genotype symbolized a lack of the D (Rh) gene. This is shown in 15% of the white population and 7% of the black population. The genotypes r'r, r'r", and r"r are found in < 1% of the white and black population.
When administering fresh frozen plasma (FFP), which one of the following is considered standard blood bank practice?
should be ABO compatible with recipients blood cells
HHHM is LD 2 and found in
the heart and RBCs
HMMM is LD4 and found in
the liver
MMMM is LD 5 and found in
the skeletal muscle
S. typhimurium
used to detect the alkaline slant/black deep (production of H2S) reaction (yellow/red with blackening in deep).
