Chapter 2 - Urine and Body Fluid Analysis Automation

Explain the principle of reflectance photometry

uses the principle that light reflection from the test pads decreases in proportion to the intensity of the color produced by the concentration of the test substance

Differentiate between semiautomated urine chemistry analyzers and fully automated urine chemistry analyzers

Semiautomated

• small and medium volume labs

• reagent strips are manually dipped in urine and placed on the strip reader

• reaction pads are read at the correct time, and strip moved to the waste container

• results displayed, printed, or transmitted to an LIS

• auto QC checks

• self calibrating

• tests for leukocyte, nitrite, protein, blood glucose, specific gravity, etc.

Automated

• high volume labs

• similar to assembly line, samples move through different stations

• sample identification, mixed, and aspirated

State the advantages of automated microscopy methods over manual microscopy methods for analyzing urine sediment

user-friendly, more cost effective, better TATs, < 1 minute vs 6 minutes, report is sent directly to the LIS or printed out, can independently perform both physical and chemical testing, microscopy and a combination of both

flow cytometry and digital imaging techniques

What 3 components are the chemical makeup of urine that can be tested for

BUN - blood urine nitrogen

Uria

Ammonia

Describe laser-based flow cytometry, digital imaging, and auto particle recognition technologies used in automated urine microscopy analyzers

laser-based flow cytometry = fluorescent, measures forward-scattered, side-scattered, and fluorescence light characteristics of particles present in urine. this info us used to detect and identify stained urine sediment particles

digital imaging = designed to capture detailed images of urine samples that require further review, all images are classified based on size into 8 different classes, then the technologist reviews the captured images

auto particle recognition (APR) = used to categorize and count urine particles automatically in uncentrifuged urine based on size, shape, texture, and contrast, the instrument can also be used for counts of body fluid cells by adding the optional body fluids software module

Discuss the advantages of automated body fluid analyzers over the Neubauer hemocytometer for body fluid cell counts

using a hemacytometer is labor-intensive and time consuming, and often they are subject to technologist variability

automation brings quality control, precision faster TATs, and standardization of results