There are two common well heights for PCR tubes and plates:

1. High-profile (full-height; around 20.7 mm) wells are “standard” and fit in most classical thermal cyclers and real-time PCR detection systems, such as Bio-Rad's iCycler^®, iQ™ series real-time PCR detection systems, and Applied Biosystems' regular PCR systems and DNA sequencers.
2. Low-profile (around 15.5 mm) wells are the newer design that reduces the potential for condensate formation and offers advantages for light capture in fluorescence assays, low-volume reactions, and fast PCR. They have been recommended for newer instruments such as Bio-Rad's C1000 Touch™ and S1000™ thermal cyclers, CFX series real-time PCR detection systems, and Applied Biosystems' fast PCR systems.

Instruments with adjustable lids can usually use both high-profile and low-profile wells. These instruments include Bio-Rad's 1000-series and DNA Engine^® series thermal cyclers.