Testing with SimpleLab: What Is Turnaround Time (TAT)?

In the world of laboratory testing, turnaround time or “TAT” is a common phrase. In this article, we explain what turnaround time is, what factors can impact turnaround time, and why TAT varies from test to test. 

Table of Contents:

• What Does TAT Refer to?
• Why Is TAT Important?
• What Factors Impact TAT?
• Can TAT Be Expedited?
• Questions? Contact Us

What Does TAT Refer to?

In laboratory testing, turnaround time (TAT) is the time period from when samples are received and accepted at the lab to the time when reports are finalized, reviewed, and released. The time a sample spends in transit and shipping is not part of the calculated TAT.

From the time when samples are received by the lab to the time of reporting, a handful of things take place, including: 

• The client chain of custody (COC) is compared to the sample received.
• Hold times are verified (if applicable).
• The sample is logged in the laboratory information management system (LIMS)
• The sample is prepared according to the requested analytical method (filtered, acid digested, preserved, etc.). 
• The sample is then analyzed, either by an instrument or microscopically.
• Quality control (QC) checks are performed on the sample to verify accuracy of all results before it is finalized.

While some analyses can be completed very quickly — sometimes in just one or even the same day — others might require extra time (2-8 weeks). The most common turnaround time for laboratory results is about 10 business days (or two weeks), although a variety of factors can impact this standard turnaround time. 

For each testing package, we are able to estimate a standard expected turnaround and completion date. While SimpleLab testing and reporting is often completed sooner than expected, sometimes extenuating circumstances will require extra time before reports are ready.

Why Is TAT Important?

A realistic laboratory turnaround time is important to ensure analytical quality and accurate reporting. 

Whether you want to complete the sale of a home, refinance a mortgage, or are looking to test for contamination in soil, food, dust, or bulk materials, getting results back as quickly as possible is a top priority for our team. But so is accuracy: That’s why we will only provide results once all required steps (including the QA/QC process) have been completed.

What Factors Impact TAT?

Factors impacting laboratory turnaround time include:

• What’s Being Tested
• Sample Composition
• Instrument Issues
• QA/QC
• Data Entry

Different types of tests have different standard turnaround times. These depend on the analysis being run. 

For example, the number and type of analytes being tested (metals, bacteria, radiologicals, etc.), as well as the composition (clarity or turbidity, etc.) of the sample can impact TAT. 

Let’s take a closer look at common factors that impact turnaround time:

What’s Being Tested

The matrix of the sample, method of analysis, and number of methods being run in a package all impact turn around time. For routine tests/analyses (e.g., fungal direct exam tape lift), a lab can more easily expedite TATs because they have people processing these samples every single day. 

For less common methods (e.g., a soy food allergen test), a lab might group samples in batches and run them only on certain days of the week. Because the QA/QC required for 1 sample is the same as it is for 20 samples, batching allows labs to be more cost effective. Batching can limit the TAT options available. 

If a lab has to share a resource — say instruments and/or personnel — the resource may be subject to scheduling constraints.

Sample Composition

TAT varies not only across test types, but also across individual samples. 

For example, say two wipe samples are being tested for the same analytes. One of the wipe samples has a light loading on the surface (i.e. less dust); the other wipe sample is caked in heavy dirt. The second wipe may require extra time to prepare the sample before it can be loaded onto the instrument or microscopically analyzed; these types of heavily loaded samples are often referred to as “overloaded with particulate.” As a result, the second sample may have a longer turnaround time.

It is important for the lab technicians that the sample is not too overloaded before analysis begins or else the instrument can be damaged. A damaged instrument can have negative impacts on laboratory operations overall — comprehensive maintenance and re-calibration may be required — slowing progress down for days or even weeks. Laboratory technicians must take the necessary time and care to ensure that samples are prepared properly. 

Instrument Issues

Turnaround times may increase during maintenance periods. Aside from occasional issues, lab instruments must undergo routine maintenance and calibration to ensure proper functioning. Proper instrument calibration reduces bias in an instrument’s reading, and safeguards accurate data. Regular calibration is required to deliver consistent, high quality service and prolong the life of these very expensive analytical instruments.

Quality Control (QC)

Quality control (QC) is the last critical step that must occur before results can be verified and released as a final report. The QC process detects, evaluates, and corrects any errors due to instrumentation issues, environmental conditions, or technician performance before the results are reported.[1] There are an extensive number of measures in place that must be checked as part of this process.[2]

SimpleLab Quality Assurance and Quality Control

All QC protocols are critical to ensure high quality, accurate data. If any QC checks fail, it may mean that the sample needs to be re-run, re-processed or re-collected. SimpleLab is committed to delivering prompt and precise results through the rigorous application of industry best practices.

Data Entry

Different laboratories also have different ways to create the report they send to the customer. Many laboratories utilize a database to process and report their data, often referred to as a LIMS: Laboratory Information Management System. 

How quickly a lab can prepare a report depends on whether an instrument is directly connected to the LIMS or if someone has to manually transcribe data from a worksheet to the LIMS. Other tests are written in word processing or spreadsheet forms that can require a longer time to report and additional chances for transcription errors.

Can TAT Be Expedited?

In some cases, turnaround time can be expedited — often for an additional fee. However, there are some tests that cannot be expedited beyond a certain point. If you think you may require a rushed turnaround time, contact our team before you place an order to confirm we can accommodate. Typically, samples cannot be expedited once they are already at the lab or on the instruments. 

Questions? Contact Us

You can send our team a message any time at hello@gosimplelab.com and we will be standing by to help out and do our best to meet your TAT needs!