Validation

Normalized DRVVT Ratio?

George has had several conversations with frequent contributor and international expertDave McGlasson (Wilford Hall USAF Medical Center, San Antonio) about normalizing the DRVVT ratio on the laboratory’s DRVVT mean of the reference interval in accordance withZhang L, et al: A simplified algorithm for the laboratory detection of lupus anticoagulants. Am J Clin Pathol 2005;124:894–901. The author […]

Lupus Anticoagulant

How to Validate an Aggregometer

From Rrosales: I am interested in purchasing a platelet aggregometer for our hematology lab, but we don’t have an existing instrument to compare it with. Some suggested H58 NCCLS (CLSI, does not really help) but I am used to validating an instrument with an old instrument (comparison/parallel testing). Can you tell me how to start the […]

Platelet Function Testing

Fibrinogen Assay Reportable Range

Dear George, I am using an STA Compact from Diagnostica Stago. I would like you to throw some light on validating the reportable range of the fibrinogen assay which is 60–1200 mg/dl. How can I obtain plasma with such high levels of fibrinogen? Regards, Dr. Shabnam Roohi. Hello, Dr. Roohi. For assistance I went to Dr. Ali […]

Quick Question Summary: LDTs

Here is a summary of our April, 2012 Quick Question: The US FDA is planning guidelines for regulating laboratory-developed tests (LDTs). What plans have you made in response? a. We are discontinuing all LDTs: 3 (15%) b. We didn’t know this is happening: 11 (55%) c. None, this will only apply to reference laboratory LDTs: 1 (5%) […]

Quick Question Archive

POC: When to Validate High INRs

George received this question from an anticoagulation clinic coordinator last week: What value would you suggest to repeat a high fingerstick INR to a venous blood, >4.0, >5.0, etc. and why? Thank you. Here is the answer George provided: “Hello, and thank you for your question. Point of care (POC) instruments provide rapid PT/INR turnaround […]

Normal Plasma Storage

Here is a seemingly simple request from Vicki Lanigan at Niagara Health, Ontario, Canada: “I am looking for a reference for storage of normal pooled plasma (NPP, pooled normal plasma, PNP).” Vicki, this one drove me back to the books and to the package inserts for distributors Precision BioLogic Inc and George King Bio-Medical, Inc to learn the shelf life for […]

Specimen Management

Study Sites Needed

Here is a request for site studies by Lauri Ketch, Manager of New Product Development at Precision BioLogic Inc: We are presently gearing up to begin external studies for a new product, the results of which will be used in a 510(k) submission to the FDA next year. We are searching for labs to partner with for […]

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George Fritsma is a medical laboratory scientist, educator, and author. George holds faculty appointments with Rutgers University and Michigan State University, and is a member of the International Society on Thrombosis and Hemostasis, American Association of Clinical Chemists, and American Society for Clinical Laboratory Science.

Cheat Sheets from George

Quick Question