Answering the Question:

Do you fit the microplate to the magnetic bead separation block or block to microplate? Usually, customers come to us with a microplate in hand and ask us which of our MagSep Blocks will work. Most of the time it’s an easy match, but sometimes they have selected that one microplate that is hard to fit any of our blocks or those from other vendors! Let’s look at it from the other way, select the MagSep Block and then the best plate. A cart and horse analogy would fit nicely here, but I’ll restrain myself!

Deep Well Microplates

Deep Well Microplates work best with our strongest MagSep Blocks, such as the VP771MDWM-1 (the 13-bar magnet block). The shape of the well at the bottom, where the magnetic beads will be collected, and how it is positioned to the bar magnet all affect considerations for choosing the right microplate.

Regular V-Bottom

If you like the 13-bar magnet block VP 771MDWZM-1 for its separation speed and pellet collection to both sides of the well, a good well shape is the regular v-bottom. This “regular” V-shape helps to position the beads away from the well bottom, similar to how the steep V-shape bottom does (see below). Plates with the regular v-bottom are usually a 2.2 ml DWP with the square well. Examples of these 96 DWPs are from Costar (3961), Axygen (P-2ML-SQ-C) and Eppendorf (DW96/2000ul). There are probably others as well.

Steep V-Bottom

A plate like the Abgene 96 DWP (AB-0932), a 2.2 ml DWP with the square well that has a “steep” V-shape to the bottom part of the well, are the best for the 13-bar magnet MagSep Block to collect the beads in 2 pellets on opposite sides of each well positioned a good distance from the well bottom. Unfortunately, this plate has plastic protrusions underneath — these are mold “gates” from the injection molding manufacturing process — that get in the way. So an alternate MagSep Block is the VP 771MWZM-1 (the 7-bar magnet block). It’s not as fast as the VP 771MDWZM-1 but still very capable at separating mag beads from a solution to the right or left, alternately, in the wells. Use the VP 771MCWZM-1 (6-bar magnet block) for plates that have a central mold gate. As of yet, I have not found a plate that has the well shape of this Abgene 96 DWP but without the mold gates underneath. Please let us know if you know of one!

Round-Bottom

And finally, a 96 DWP with a round bottom well also works, but occasionally the collected beads may not be far enough from the bottom center of the well where your pipette tip will be for aspirating the liquid. This can happen if the concentration of beads in the solution is high or if the beads don’t stay in a tight pellet on the side of the well (most likely due to the beads not being very magnetic). These are situations we have encountered when testing bead separation for customers to create a new MagSep Block. If you find this to be the case for your assay, consider a DWP with a V-shaped well bottom.

For a longer list of 96 DWPs that have been checked for a good fit on V&P’s 13-bar magnet block (VP 771MDWZM-1) and 6-bar magnet block (VP 771MCWZM-1) please see this product note:

If you don’t see your 96 DWP on the list, send it to us and we will check it for you