# Agreement and internal quality assurance of the Neubauer hemocytometer and Makler chamber for human sperm concentration determination

## TL;DR

This study compares two devices used to measure human sperm concentration and finds that one device is more reliable than the other.

## Contribution

The study evaluates the interchangeability of the Neubauer hemocytometer and Makler chamber for sperm concentration measurements.

## Key findings

- The Makler chamber overestimates sperm concentration compared to the Neubauer hemocytometer.
- The Neubauer hemocytometer shows greater consistency and lower variability in measurements.
- The Makler chamber is less suitable for evaluating low sperm concentration samples.

## Abstract

The Neubauer hemocytometer, as well as the Makler chamber, are devices
commonly used in andrology laboratories. The present study aimed to verify
if both methods yield comparable results, and whether they can be used
interchangeably to determine sperm concentration.

Sperm and latex beads concentration measurements were performed with the
Neubauer hemocytometer and the Makler chamber. Fixed and proportional biases
were estimated, and the method agreement was determined by assessing sperm
concentration results with the Bland and Altman plot. The Coefficient of
Variation (CV) and relative bias were calculated as an index of precision
and accuracy, respectively, by measuring latex beads target concentrations
in both chambers.

The Makler chamber systematically overestimated the Neubauer hemocytometer
concentration measurements by a mean of -7.99%, with limits of agreement
(LOA) between -41% to 25.61% (p<0.001). The fixed bias
was found for concentration values inferior to 40 x 106/ml range
(p<0.001), but not higher concentration results
(p>0.05). Measurements with the Neubauer
hemocytometer showed the greatest consistency in the study with the CV
ranging from 3.01% to 6.67%; while the CV with the Makler chamber ranged
from 8.46% to 25.64%. The relative bias for the Neubauer hemocytometer
determinations varied from 0.12% to 8.40%, while for the Makler chamber
varied from 7.6% to an overestimation of 38.0%.

Measurements made with the Makler chamber demonstrated more variability and a
higher degree of overestimation. The Makler chamber is a poor substitute to
the Neubauer hemocytometer for evaluation of oligozoospermic samples,
although both chambers render similar results for highly concentrated
samples.