MACSima™, the spatial biology platform from Miltenyi Biotec

How it works & what we need to consider

I recently got to learn about Miltenyi Biotec's new spatial biology tool, MACSima™ imaging system, from a rep in Portugal¹. In this blog, I'll explain how it works and what we should consider before using it.

Principle 🔄

MACSima™ is based on Imaging Cyclic Staining (MICS). It involves automated cycles of fluorescent staining, imaging, and signal erasure (Fig. 1). In each 🔄, the samples are stained with a unique set of 3 fluorochrome-conjugated antibodies. The system captures images of the stained samples and then removes the fluorescence signal. This process is repeated automatically for multiple cycles. At the end, we will have a stack of images with different protein expression markers.

Figure 1: MACSima cyclic staining. https://www.miltenyibiotec.com

Instrument

The MACSima™ instrument is a compact, fully automated platform for handling samples and collecting data on protein expression. It is composed of:

• Liquid handling system, ideal to eliminate pipetting errors and save reagents

• Ultra-precise stage, where our samples will be placed and almost everything will happen

• Fluorescent 🔬. Includes 1 objective for quick scans and two 20x objectives for detailed views

• 1 scCMOS camera (scientific complementary metal-oxide-semiconductor camera)²

• 2 computers for storing and analyzing our data

Samples

For the moment, with MACSima™, we can use human and 🐭 🐭 tissues, adherent, or suspension cell lines. All biological materials need to be fixed. The validated fixation methods for the moment are: acetone, paraformaldehyde (PFA), and formalin-fixed paraffin-embedded (FFPE).

Sample Carriers (MACSwell)

The sample carriers (Fig.2) are physical supports/adapters that we will need to use to create reaction chambers (cavities). Depending on the type of sample, we will have to choose between:

1. 24 Imaging plates: plates with 24 wells where we can grow adherent cells

2. Imaging frames: 3 types of frames. With 1, 2, or 4 independent reaction cavities. The frame will be placed around a standard 🔬 slide that will contain our sample(s)

3. Micro Slides: slides that contain 1.5 million hexagonal microcavities, sized to fit 1 cell. With it, we will need to use one of the imaging frames described previously

Figure 2: Sample Carriers (MACSwell); adapted from MACSima Platform brochure & https://www.miltenyibiotec.com

MACSima™ Antibodies

On this platform, we can use 3 types of fluorochrome-conjugated antibodies.