Introduction

Maintaining a laboratory inventory is an important but often underestimated task in research—yet it plays a critical role in the efficiency of labor. Inaccuracies in inventory tracking can lead to mistrials, delays, financial loss, and compromised data integrity [1]. Developing a reliable and efficient inventory system is essential for ensuring smooth experimental operations and maintaining optimal research quality.

Many laboratories track inventory in one of three ways, either through Excel® spreadsheets and Google Sheets®, sheets of paper, or via paid subscriptions to laboratory information management systems (LIMS) [2]. Systems brought forward through the use of LIMS, have paved way for advanced functionalities for tracking samples, managing data, and streamlining workflows. However, despite their growing popularity, these laboratory management systems may have shortcomings such as high cost, steep learning curves, and lack of customization [3]. These gaps have driven the continuous development of alternative solutions such as those that tap into the ever-changing advantageous environment brought by technology and mobile devices. Handheld mobile devices have the ability to act as scanners through the use of their camera features, opening the door for an inventory management system which parallels that seen in retail environments [4,5].

To address these gaps, this work introduces LIME: a cost-effective, mobile-centric, and spreadsheet-integrated system for inventory management. LIME enables users to submit inventory data through mobile forms with information seamlessly transmitted to Excel^® or Google Sheets^®. This eases adoption as these tools already widely used and understood by the public and academic labs [2]. This dual-interface design harnesses the speed and convenience of mobile devices while retaining the flexibility and widespread use of spreadsheets.

Structural features

LIME works via communication between the mobile app as the input node and the in-the-cloud spreadsheet as the processing and data storage element (Fig 1). Through their mobile devices, users download an app, Scan-IT to Office^®, to establish a connection with the spreadsheet located in a cloud storage service selected by the user. Through the app, the user creates a “form” with a series of varying inputs at their needs. Along with the inventory template, the users also receive a set of instructions guiding them on how to create the forms. Complete user documentation is available in the Supplemental Material S1 File.

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Fig 1. Workflow summary of LIME.

The Scan-IT to Office^® phone/tablet application scans the item barcode. Once the barcode is read, the user fills the rest of the information fields. This information is transferred to the in-the-cloud spreadsheet log tab as a timestamp. The categorical spreadsheet tabs (e.g., “1_Chem”, “2_Flame”, etc.) tally the items based on their net quantity by calculating the net additions and subtractions of each item.

https://doi.org/10.1371/journal.pone.0336412.g001

In the Excel^®/Google Sheets^® spreadsheet, a sheet titled “Log” keeps the “checks and balances” of the inventory. Among one of the input fields indicated on the forms, users create an “inventory ID” which serves to group/tag items that are being logged into user predefined categories such as the physical location of a set of items.

The formulas implemented here on the spreadsheet further organize the materials into different catergorical tabs at the user’s discretion (e.g., chemical tab, −20 ºC tab, etc.) (Fig 2). Once the tabs have been decided, one must adjust the tab identifier name withing the formula from “1_Custom” to the desired element name in the spreadsheet tab that will match the name to be listed in the phone app. For example, if one tab is declared to be the chemicals tab, it could be written as “1_Chem” in the spreadsheet formula and the form entry named "INVENTORY ID" on the app. The usefulness lies in organizing the inventory into different sheets that may represent the physical location to these items. This facilitates the location of an item, as it sorts items based on their uniquely assigned barcode number. Barcode systems offer users an advantage in efficiency and fast acqusition by scanning devices, while simultaneously improving accuracy [4].

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Fig 2. Visual appearance of LIME.

(A) The LIME template on MS Excel® and (B) the form on the Scan-IT to Office^® app. Google Spreadsheet and Android® equivalents are not shown as they are visually similar.

https://doi.org/10.1371/journal.pone.0336412.g002

User survey

The survey was done using Qualtrics®. The survey study was approved by the Florida State University Institutional Review Board (IRB) and the study was registered under the identification number STUDY00005647. Participant recruitment for the survey was conducted from March 1 to April 16, 2025, during which eight participants were enrolled. Verbal consent was obtained and documented in the presence of a witness prior to system testing. All data were collected anonymously to ensure participant confidentiality and were accessed only after the completion of all surveys, which was after April 16^th, 2025.

Results and discussion

Here, LIME is presented as a free, open-source software tool designed to improve laboratory inventory management by reducing tracking time, improving accuracy, and minimizing reagent shortages. LIME offers substantial improvements over existing inventory management systems by prioritizing simplicity and combining advanced features like barcode integration and visible alerts with a user-friendly interface. Data entry is simplified through QR and barcode scanning, which reduces manual error and provides dynamic updates to inventory databases [6]. Custom fields in the form allow users to classify and separate inventory by lab-specific categories, improving searchability and organization.

An often-overlooked advantage of this approach is accessibility. Because LIME relies on universally available platforms and mobile technology, it garners a strong potential for wide adoption, not only in academic labs but also in startups and institutions with limited resources. Research shows that mobile-centric systems offer ergonomic, scalable, and cost-efficient solutions that align well with modern digital environments [7]. To demonstrate LIME’s effectiveness, a user guide was created and paired with a downloadable spreadsheet template (See Supplemental Material S1 File). This system was deployed across a number of research laboratories. User experience, perceived utility, and proficiency were measured through a series of follow-up questions. The survey revealed a net positive reception for LIME (Fig S1-S7 in S2 File), with 87.5% as moderately easy to set up (Fig S1 in S2 File), 75% describing it as extremely accurate and/or very accurate (Fig S4 in S2 File), and 75% describing that they will continue to use LIME (Fig S7 in S2 File). This suggests that the system has favorable functionality. Importantly, most users indicated that this system is on par or superior to their current laboratory inventory management system (Fig S3 in S2 File). This is noteworthy as the goal of this system is to offer a freely accessible inventory management system that can be adopted with minimal training.

The ability to track usage patterns and visualize data in real time provides researchers with the tools needed for better budgeting and resource allocation. Its open-source and multi-platform nature ensures that it can be adapted to suit various laboratory types and scales, with the potential for continuous improvement through community contributions. With its flexible, scalable design and open-source license, LIME represents a valuable contribution to laboratory efficiency and resource management. Future developments will focus on expanding its features based on user feedback and ensuring its long-term viability through community-supported updates.

Despite all the benefits highlighted, LIME has a number of limitations to consider. First, the connectivity to the phone app cloud is slow due to the latent time of the cloud server refresh. Second, the spreadsheets are prone to having incorrect information being inserted by inexperienced users. It is highly recommended that the management of supply inputs and outputs from LIME be done by full-time laboratory members rather than part-time students to maintain concistency and an up-to-date inventory. Third, since the version that is used for the app is free, at random times, a prompt message stating “DEMO - Please subscribe to use full version” appears into a cell in the spreadsheeet, which does not input the data that was recently entered. If this happens, one must rescan the item again. Other errors such as “Internal error” appear, but the data usually is transfered to the spreadsheet. If not, the ‘History’ option on the app will save that input and will give the user the option to resend. In other cases, one can use the ‘log’ tab on the spreadsheet as a version control to check for incorrect information inputs. Overall, these are limitations that are part of the compromise of making a system free and accessible to use from widely available software tools.

Supporting information

Acknowledgments

The authors wish to thank the survey participants. This project was funded by startup funds from the Department of Health, Nutrition, and Food Science (C.S.).