5.4 - Fundamental Concepts of TQM (Quality Control Materials)

Question 1

These are specimens that are analyzed for QC purposes. It is with a known unchanging __________and physically resembling the unknown samples. It is commonly tested prior to the testing of series of unknowns or patient samples. It is used to monitor the stability of the test system within _________limits. Known values are usually presented by an interval of acceptable values, or upper and lower limits for control (control limits). When observed values fall within the control limits, the analyst is assured that the analytical method is functioning properly.

Answer 1

concentration; predetermined

Question 2

These are commonly supplied as ________, frozen or ________materials that are reconstituted with water or a specific diluent solution. _________ control materials have the advantage of eliminating errors caused by reconstitution. However, the matrices of these materials may contain other materials that are potential source of error with some analytical methods and instruments.

Answer 2

liquid; lyophilized; Liquid

Question 3

______ or ______ materials should be selected to provide concentrations that monitor performance at different medical decision levels (representative of low abnormal, normal, high abnormal values).

Answer 3

Two; three

Question 4

Desired characteristics of a QC Material include:

(1) Analyte concentration should be at medically significant levels. The concentration of analyte should be in ______ and ________levels, corresponding to concentrations that are critical in the medical interpretation of test results.

Answer 4

normal; abnormal

Question 5

Desired characteristics of a QC Material include:

(2) Material should be available in large quantities but in ______or ______. The size of the aliquots or vials should be convenient for analytical methods to be monitored. While larger vials are ________. The tendency of leaving unused samples may eliminate any savings. Once a reconstituted QC material aliquot has been thawed it cannot be refrozen and be reused.

Answer 5

aliquots; vials; cheaper

Question 6

Desired characteristics of a QC Material include:

(3) Material matrix should be similar to the human sample as possible. __________ matrix may be best when serum is the test material to be analyzed. Materials from human sources (“pooled sera”) have generally been preferred but because of the risk of of ___________ infection, bovine and synthetic materials offer a certain advantage in safety.

Answer 6

Protein; hepatitis

Question 7

Desired characteristics of a QC Material include:

(4) Constituents should be stable for a long period of time. It is desirable to purchase a year’s supply of ______ manufacturing batch or lot . Different batches (or lot numbers) of the same materials will have different concentrations which requires new estimates of mean and standard deviation

Answer 7

one

Question 8

Desired characteristics of a QC Material include:

(5) Material should have a ______ vial-to-vial variability so that differences between repeated measurements are attributed to the analytical method alone.
(6) If prepared, it should be stable for the period of use.
(7) Requires minimum preparation.
(8) Readily available.
(9) Reasonably priced.

Answer 8

low