Sample Collection & Processing Best Practices For Labs

‘'If it's not documented, it didn't happen.”

This old adage takes on new meaning when you're responsible for both collecting and testing samples.

Unlike labs that simply receive samples, your chain of custody begins the moment you collect. But as your lab scales and throughput increases, the chance that something slips through the cracks (sometimes literally) increases as well. This has downstream consequences on meeting regulatory compliance standards as well, making proper sample collection a non-negotiable.

For manufacturing, quality control, environmental, and research labs, your success depends on how you reliably collect and manage samples. This guide details the best practices and guidelines your staff must follow for optimal and orderly sample collection and management. Protect your lab’s reputation and deliver consistent, accurate results with the guidelines below.

Sample Collection and Processing Best Practices

While complete guidance on sample collection will depend on your lab and the samples you collect, the following guidelines are a good head start:

• Documentation and labeling
• Storage
• Preparation
• Safety and disposal
• Quality control

Documentation and Labeling to Ensure Reliable Results

Sample collection starts with the orderly documentation and cataloging of every sample that enters your lab.

Every sample needs a unique identifier. This could be a combination of the date, sample type, and sequential number, but it’s key that you have a convention your staff follows for every sample. Most, if not all, regulations require samples to have unique identifiers, making it an essential practice to maintain compliance. Don’t forget to use durable and water-resistant labels if necessary; the last thing you need is smudged ink or a damaged label rendering a sample useless.

If your lab does not already use a digital record to log samples (and other data), we recommend investing in software to automate some of these processes. With dedicated lab software, you can do much more with label printing, barcode scanning, and automatic tracking than you could manually.

Proper Storage to Maintain Sample Integrity from Collection to Analysis

Once collected and tagged, you must ensure that every sample is stored under the right conditions, kept at the right temperature, and that its location is documented. 

We recommend using clearly marked storage zones, maintaining inventory logs, and implementing first-in-first-out systems where applicable. Again, this is where software can help over manual logs, which can quickly become out of date.

To ensure the integrity of your samples, regularly check storage conditions and set up alerts for out-of-range conditions. To guard against power outages, redundant power supplies and other backup systems may also be necessary.

Proper Sample Preparation for Accurate Testing

Sample preparation starts with proper documentation and identification. Each sample must be labeled with at least two unique identifiers and follow a consistent naming convention.

If Chain of Custody documentation is necessary for the procedure, follow the appropriate protocol. All specimens should be labeled in the presence of the patient. Chain of Custody (CoC) protocols protect both the patient (if the context is clinical) and the lab from liability. Process and store the specimen(s) as required. Appropriate storage and handling are necessary to maintain the integrity of the specimen and, consequently, the test results.

Safety and Disposal: Protect Your Lab and the Environment

Sample collection and management involve more than just collecting samples when you need them in your lab; you also need to take special care when they are disposed of. 

Your staff must follow recommended sterilization procedures, including precautions regarding the use of needles and other sterile equipment. Treat all biological material as potentially hazardous, along with contaminated collection supplies. 

For specific guidelines, we recommend following the OSHA guidelines for lab safety, which cover:

• Work practices and PPE usage
• Biological hazards
• Chemical hazards
• Equipment hazards

Following these guidelines protects your staff, keeps everyone safe, and helps your lab meet regulatory compliance standards.

Quality Control For Consistency and Compliance

Finally, quality control must be at the heart of every activity in your lab. 

Quality control is an exhaustive topic in its own right, though there are a few quick tips we’d recommend to ensure you are handling and monitoring samples correctly:

• Include blank samples, duplicates, and reference materials with each batch of samples processed.
• Calibrate instruments and equipment frequently
• Record all QC results, including deviations and corrective actions
• Define clear pass/fail criteria for controls and document steps to take for any failures
• Maintain training records and conduct regular assessments for your staff

Maintaining good quality control helps protect the integrity of your lab’s data, reduce delays, and meet regulatory requirements in your industry. Consistent QC improves turnaround times (TAT) as well.

Sample Collection: The Basic Steps to Follow

The exact steps to follow will depend on the specific type of sample you wish to collect, but whether it be blood, saliva, or water, the following will give you a basic framework for collecting samples in your lab:

Prepare the Sample

First, ensure that you have the appropriate container for your sample and that it is clean and sterile if necessary. Wear appropriate PPE, including gloves and eye protection if required. Make sure your workspace is clean and organized and your sample collection form (or LIMS, Lab Information Management System) is ready for data entry.

Collect the Sample

When collecting the sample, make sure to label it with the following:

• A unique ID
• Date and time of collection
• The type of sample
• Your initials/identifier
• Any required preservatives or storage conditions

Use the appropriate collection tools and techniques for your sample type and follow the guidance on the amount required for your tests. Also, avoid cross-contamination between samples and follow the guidance on any preservatives you use.

Document the Sample

When documenting samples in your lab, record all relevant information immediately and document environmental conditions if relevant. It’s also worth noting any observations about sample appearance or collection conditions.

Post-Collection

Once your sample is collected, seal containers properly (do not over-tighten) and verify all labels are complete and legible. Transfer the sample to the appropriate storage area in your lab and complete chain of custody forms if required.

Common Pitfalls to Avoid When Handling Samples in Your Lab

There are obvious errors when it comes to collecting samples in your lab, like knocking a sample off your workbench and spilling it on the floor. 

Incidents can happen at any time, but the following are the subtle pitfalls that can plague your lab and cause delays:

• Improper sample identification: This includes missing or incomplete labels, illegible handwriting, or labels that degrade during storage. These errors can lead to sample mix-ups or invalidation of results, potentially requiring recollection or causing serious diagnostic errors.
• Temperature control failures: Not maintaining proper temperature during collection, transport, or storage can compromise sample integrity. This includes leaving samples at room temperature too long, freezer failures without backup systems, or improper shipping conditions.
• Documentation gaps: Poor documentation practices like missing collection times, incomplete chain of custody records, or failure to note deviations from standard procedures can invalidate results and create regulatory compliance issues.
• Cross-contamination: Improper handling techniques, using wrong collection containers, or poor storage organization can lead to sample cross-contamination. This is particularly critical in microbiological and molecular testing.

You can avoid many of these pitfalls with proper tools in your lab, like a LIMS.

Level up Sample Management with a LIMS

Thanks to increased throughput and regulatory requirements, sample collection can quickly become a complex task for labs. That complexity is magnified if you still rely on manual data entry. 

A LIMS is a comprehensive platform designed to centralize and digitize all the information of your lab, automate processes, and monitor samples at every stage. With a LIMS, you can generate labels, record them, monitor their location, and alert your staff of any storage issues while you focus on more important tasks at hand. 

If you’re ready to move beyond the manual grind of spreadsheets and select a LIMS to streamline inventory management, sample management, and manual processes for your lab, then download our free LIMS Buyer’s Guide to help you choose the right LIMS for your lab.

Click the button below to download the free buyer’s guide and take the first step toward improving your lab’s inventory management processes.