CLN - The Sample
Experience level and task sensitivity significantly influence pipetting performance, recent research shows (J Appl Lab Med 2026; doi.org/10.1093/jalm/jfag006).
The researchers call for ongoing training and performance assessment for all laboratory staff, because even experienced personnel involved in the study occasionally failed to meet International Organization for Standardization (ISO) standards.
Accurate and precise pipetting is crucial for reliable laboratory results, especially when small volumes or sensitive analytical techniques are involved. Despite common use of piston-operated pipettes, operator-dependent variability remains a major source
of error.
To assess the effect of experience level on pipetting, the researchers conducted what they describe as the first study to comprehensively assess manual pipetting performance using both gravimetric and photometric methods across a large and diverse cohort of participants.
The researchers evaluated pipetting performance among laboratory personnel with varying levels of experience. The study had 108 participants, including laboratory school students, PhD students, clinical chemists, and laboratory technicians. They were stratified into three groups: those with minimal experience, moderate experience, and high-level experience. The researchers evaluated pipetting performance using gravimetric replicates at 10 µL and 100 µL volumes and a dilution task involving serial dilutions of 1 M copper sulfate. Then they compared accuracy and precision metrics across the groups.
The median coefficient of variation was lower for 100 µL replicates (0.3–0.8%) than for 10 µL replicates (1.4–5.9%). Laboratory students showed the greatest variability and longest task completion times, suggesting that inexperience and limited hands-on practice are key contributors to low reproducibility and accuracy. However, students’ performance improved the longer they'd been in school. Ten percent of participants exceeded ISO-defined accuracy limits for 10 µL pipetting, and 22% for 100 µL. Additionally, 36% and 20% of participants surpassed imprecision limits for 10 µL and 100 µL, respectively. The group with high-level experience achieved optimal dilution performance, while students showed the highest deviation.
Training programs should emphasize techniques for low-volume pipetting, regular proficiency evaluations, and refresher training that incorporates gravimetric and dilution-based assessments for all laboratory personnel, the researchers suggested.
A closer examination of the APOL1 gene in patients with chronic kidney disease (CKD) can determine the cause of their kidney disease more effectively and potentially alter diagnosis, risk stratification, transplant evaluation, and treatment, recent research shows (JAMA Netw Open 2026; doi:10.1001/jamanetworkopen.2026.1452).
The APOL1 M1 variant protects against focal segmental glomerulosclerosis (FSGS) and CKD associated with the G2 variant of APOL1. However, knowing whether an individual’s M1 status can help guide kidney disease diagnosis and other clinical scenarios remains underexplored.
The researchers aimed to determine whether that status could help identify the true cause of a patient’s kidney disease. They examined the health records of approximately 107,696 individuals with a diagnosis of FSGS or CKD from two large academic medical centers, the UK Biobank, and the National Institutes of Health’s All of Us Research Program. Of the total, 8.2% had African ancestry, 72.9% had European ancestry, and 15% had multi-ethnic ancestry. The study included 3,460 participants with FSGS or steroid-resistant nephrotic syndrome (SRNS), 24,382 with non-FSGS CKD, and 79,854 controls enrolled in the discovery cohort.
After reviewing medical records and available biopsy data, the researchers found that nearly all patients with CKD who carried both an APOL1 high-risk (HR) genotype and M1 did not have APOL1 kidney disease. In the APOL1-HR group, M1 demonstrated an inverse association with FSGS or SRNS cases, compared with controls without kidney disease. Among individuals with CKD and APOL1-HR genotypes, M1 was four times more frequent in those whose CKD was not FSGS or SRNS.
Electronic health record and biopsy review identified an alternative, non-APOL1 cause for CKD in nearly all APOL1-HR-M1 cases. The study found no association between individuals with APOL1 low-risk genotypes with M1 and protection against CKD or FSGS.
The research also showed that the APOL1-HR-M1 genotype was significantly associated with protection against kidney disease. The finding suggests that it may have a role as a genetic modifier.
Patients with CKD with an APOL1-HR genotype and M1 should be evaluated for an alternative and potentially treatable cause of their CKD, the researchers said.