ASCP-MLT Online Practice Questions and Answers

The recommended disinfectant for blood and body fluid contamination is:

A. sodium hydroxide.

B. antimicrobial soap.

C. hydrogen peroxide.

D. sodium hypochlorite.

Set of comprehensive safety guidelines designed to protect patients and health care workers

A. Standard Precautions

B. Universal blood precautions

C. Microscope

D. Transmission precautions

One of the key characteristics to the identification of Nocardia asteroides is its inability to hydrolyze casein, tyrosine or xanthine, as shown in this photograph. Nitrates are reduced to nitrites. Both Nocardia brasiliensis and Actinomadura madurae hydrolyze both casein and tyrosine; Streptomyces griseus hydrolyzes all three of the substrates.

Illustrated in this photograph is an agar quadrant plate containing casein (A), tyrosine (B), nitrate (C) and xanthine (D). None of the substrates have been hydrolyzed and nitrate has been reduced. The most likely identification is:

A. Nocardia asteroides

B. Nocardia brasiliensis

C. Streptomyces griseus

D. Actinomadura madurae

Malbranchia species share the production of alternate staining arthroconidia as a common feature with the mold form of Coccidioides immitis.

Both Geotrichum species and Trichosporon species produce rectangular-shaped arthroconidia; however, they are regularly rather than alternately staining. Additionally, the arthroconidia of Geotrichum may produce germ tubes from one

corner and the arthroconidia of Trichosporon species may produce blastoconidia from adjacent corners, features not shared by either Malbranchia species or Coccidioides immitis.

The hyphae of Microsporum canis, as seen in direct KOH mounts of skin scales, may break up into arthroconidia; however, they are much narrower in dimension and do not share the alternate staining characteristics.

Microbiology

The hyaline saprobic fungus that has microscopic features similar to the mold form of Coccidioides immitis is:

A. Malbranchia species

B. Geotrichum species

C. Trichosporon species

D. Microsporum canis

Rule-out is a process by which antibodies are identified as being unlikely in a given sample because of the absence of an expected antigen-antibody reaction. In other words, the absence of a reaction is noted with a cell that is positive for the

corresponding antigen.

Although rule-out procedures may vary somewhat from institution to institution, the following general principles apply:

Non-reactive cells are selected for rule-out. To be classified as non-reactive, a cell must NOT have reacted at any phase of testing in a given panel or screen.

Using the logic that if the rule-out cell is positive for a given antigen, it should have reacted with the corresponding antibody, you can rule-out antibodies that correspond to antigen positive cells.

To increase the probability that rule-out will not mistakenly eliminate a weakly-reacting antibody that exhibits dosage*, use only cells that are homozygous for the corresponding antigen for those systems that generally show dosage. Generally

these include: C, c, E, e, Fya, Fyb, Jka, Jkb, M, N, S, and s.

In this case, it is only possible to rule out on screening cell 2 since it demonstrates a negative reaction with the patient serum. Anti-C cannot be ruled out since the C antigen is heterozygous on screening cell 2 with c. Anti-Fya cannot be ruled out since this antigen is not present on screening cell 2. Anti-M and anti-Jka can be ruled out since the antigens are homozyous while demonstrating a negative reaction on screening cell 2.

Rule-out, while very useful, can lead to error. Ruling out an antibody should be combined with other supporting data to increase confidence in the solution; the more data collected, the higher the probability that the final solution is correct.

*Dosage means that there are two "doses" of the same antigen present on the red cells . Antibodies that exhibit dosage react more strongly with homozygous cells (e.g., Jka Jka) than with heterozygous cells (e.g., Jka Jkb) .

Based on the phenotype of the RBC screening cells, and patient results shown on the right, which of the following antibodies CANNOT be ruled out?

A. Anti-C

B. Anti-Jka

C. Anti-M

D. Anti-Fya

Cryoglobulin testing can be used to:

A. Screen for rheumatoid arthritis

B. Screen for systemic lupus erythematosus (SLE)

C. Help diagnose Raynaud's syndrome

D. Diagnose syphilis

Blood bank

Once the seal on a unit of packed red cells is broken, how long can the unit be stored refrigerated prior to administration:

A. 4 hours

B. 12 hours

C. 24 hours

D. 48 hours

The role of the point-of-care testing (POCT) compared with in-laboratory testing is the

A. Specific microscopic tests (wet mounts) performed by a physician for his or her own patients

B. Process of performin laboratory testing at the bedside of the patient and a means of decentralizing some of the laboratory testing

C. Means by which quality control between laboratories is maintained

D. Continuation of the process of evaluating and monitoring all aspects of the laboratory to ensure accuracy of test results

The personal protective equipment (PPE) that is used in the laboratory to protect the personnel when performing tests on patient blood samples is which of the following:

A. Gloves

B. Coat or gown

C. Goggles and mask

D. A and B only

The coagulation department tests samples for:

A. prothrombin times

B. bacterial growth

C. electrolytes

D. complete blood counts