Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy
Urinary tract infections are among the most frequent infectious diseases and require screening a great amount of urine samples from patients. However, a high percentage of samples result as negative after urine culture plate tests (CPTs), demanding a simple and fast preliminary technique to screen o...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-08-01
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| Series: | Biosensors |
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| Online Access: | https://www.mdpi.com/2079-6374/13/8/789 |
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| author | Lucia Gigli Nicoletta Braidotti Maria Augusta do R. B. F. Lima Catalin Dacian Ciubotaru Dan Cojoc |
| author_facet | Lucia Gigli Nicoletta Braidotti Maria Augusta do R. B. F. Lima Catalin Dacian Ciubotaru Dan Cojoc |
| author_sort | Lucia Gigli |
| collection | DOAJ |
| description | Urinary tract infections are among the most frequent infectious diseases and require screening a great amount of urine samples from patients. However, a high percentage of samples result as negative after urine culture plate tests (CPTs), demanding a simple and fast preliminary technique to screen out the negative samples. We propose a digital holographic microscopy (DHM) method to inspect fresh urine samples flowing in a glass capillary for 3 min, recording holograms at 2 frames per second. After digital reconstruction, bacteria, white and red blood cells, epithelial cells and crystals were identified and counted, and the samples were classified as negative or positive according to clinical cutoff values. Taking the CPT as reference, we processed 180 urine samples and compared the results with those of urine flow cytometry (UFC). Using standard evaluation metrics for our screening test, we found a similar performance for DHM and UFC, indicating DHM as a suitable and fast screening technique retaining several advantages. As a benefit of DHM, the technique is label-free and does not require sample preparation. Moreover, the phase and amplitude images of the cells and other particles present in urine are digitally recorded and can serve for further investigation afterwards. |
| first_indexed | 2024-03-11T00:05:13Z |
| format | Article |
| id | doaj.art-2ff975eff3d64600b2deae9e4681ebd9 |
| institution | Directory Open Access Journal |
| issn | 2079-6374 |
| language | English |
| last_indexed | 2024-03-11T00:05:13Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biosensors |
| spelling | doaj.art-2ff975eff3d64600b2deae9e4681ebd92023-11-19T00:25:13ZengMDPI AGBiosensors2079-63742023-08-0113878910.3390/bios13080789Label-Free Analysis of Urine Samples with In-Flow Digital Holographic MicroscopyLucia Gigli0Nicoletta Braidotti1Maria Augusta do R. B. F. Lima2Catalin Dacian Ciubotaru3Dan Cojoc4Alifax s.r.l. Via Merano, 30, Nimis, 33045 Udine, ItalyConsiglio Nazionale Delle Ricerche (CNR), Istituto Officina dei Materiali (IOM), Area Science Park-Basovizza, Strada Statale 14, Km 163,5, 34149 Trieste, ItalyConsiglio Nazionale Delle Ricerche (CNR), Istituto Officina dei Materiali (IOM), Area Science Park-Basovizza, Strada Statale 14, Km 163,5, 34149 Trieste, ItalyConsiglio Nazionale Delle Ricerche (CNR), Istituto Officina dei Materiali (IOM), Area Science Park-Basovizza, Strada Statale 14, Km 163,5, 34149 Trieste, ItalyConsiglio Nazionale Delle Ricerche (CNR), Istituto Officina dei Materiali (IOM), Area Science Park-Basovizza, Strada Statale 14, Km 163,5, 34149 Trieste, ItalyUrinary tract infections are among the most frequent infectious diseases and require screening a great amount of urine samples from patients. However, a high percentage of samples result as negative after urine culture plate tests (CPTs), demanding a simple and fast preliminary technique to screen out the negative samples. We propose a digital holographic microscopy (DHM) method to inspect fresh urine samples flowing in a glass capillary for 3 min, recording holograms at 2 frames per second. After digital reconstruction, bacteria, white and red blood cells, epithelial cells and crystals were identified and counted, and the samples were classified as negative or positive according to clinical cutoff values. Taking the CPT as reference, we processed 180 urine samples and compared the results with those of urine flow cytometry (UFC). Using standard evaluation metrics for our screening test, we found a similar performance for DHM and UFC, indicating DHM as a suitable and fast screening technique retaining several advantages. As a benefit of DHM, the technique is label-free and does not require sample preparation. Moreover, the phase and amplitude images of the cells and other particles present in urine are digitally recorded and can serve for further investigation afterwards.https://www.mdpi.com/2079-6374/13/8/789urine analysisdigital holographic microscopybacteria detectionurinary tract infectionsample screening |
| spellingShingle | Lucia Gigli Nicoletta Braidotti Maria Augusta do R. B. F. Lima Catalin Dacian Ciubotaru Dan Cojoc Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy Biosensors urine analysis digital holographic microscopy bacteria detection urinary tract infection sample screening |
| title | Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy |
| title_full | Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy |
| title_fullStr | Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy |
| title_full_unstemmed | Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy |
| title_short | Label-Free Analysis of Urine Samples with In-Flow Digital Holographic Microscopy |
| title_sort | label free analysis of urine samples with in flow digital holographic microscopy |
| topic | urine analysis digital holographic microscopy bacteria detection urinary tract infection sample screening |
| url | https://www.mdpi.com/2079-6374/13/8/789 |
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