It was invented and made by Harold Whitlock, at the CSIRO McMaster Laboratory, Australia. His son, John Whitlock, continued to make the slides until about 2022, but retired and ceased manufacture.

The Maxwell Universal WEC Slide is the same design as the Whitlock Universal, but is made from acrylic instead of glass, making it cheaper and resistant to breakage.

Features

• Precision laser-etched grids on the undersurface of the top (not printed, so the lines do not wash or wear off)

• 4 chambers, each with grids of 0.5 ml volume and a total capacity of 2 ml per slide.

• Slide dimensions are 76 mm x 33.5 mm x 6 mm (same as the Whitlock version)

Don’t be confused about slide names

“McMaster” slides sold elsewhere at an old design of Harold Whitlock’s, with only 2 chambers, each with only 0.15 ml volume under each grid.

To count the same amount of faeces (and achieve the same sensitivity) involves either preparing more of these smaller chambers resulting in more time spent preparing, counting and cleaning, or else increasing the faeces/salt solution concentration, making the solution darker and harder to identify eggs.

Whitlocks stopped making the McMaster slide design in favour of the Universal slide due to its benefits.