ExKine™ Nuclei Extraction Kit (High Purity) (KTP4002) — Product Review & Buying Guide for Single-Nucleus Genomics Researchers

When Your 10x snRNA-seq MtRatio Hits 28%, the Problem Is the Nuclei, Not the Library Prep

Single-nucleus RNA-seq and snATAC-seq have a brutal quality metric: mitochondrial read ratio (MtRatio). A clean nuclei prep yields <5–10% mitochondrial reads; a contaminated prep — nuclei carrying cytoplasmic mitochondria, ER membrane fragments, or adipocyte lipid droplets — can push MtRatio past 25–30%, wasting sequencing depth and obscuring the biology[reference:31]. The culprit is almost never the library kit. It is the nuclei isolation step.

The ExKine™ Nuclei Extraction Kit (High Purity) (KTP4002) from Abbkine is designed for exactly this failure mode: pure nuclei and fragile nuclei from mammalian cultured cells and solid tissues, collected by ultracentrifugation through a dense sucrose cushion that protects nuclei while stripping away membranes and cytoplasmic contaminants[reference:32]. With >95% nuclear enrichment and a price of 2.45 per sample), it is a cost-effective fix for snRNA-seq and snATAC-seq input quality[reference:33]. Here's our detailed review.

What's in the Box?

A four-component kit built around the sucrose-cushion purification principle.

Advantages

1. Sucrose Cushion Ultracentrifugation — The Purity Difference

The kit's core advantage is the 1.8 M sucrose cushion: nuclei are pelleted through a dense sucrose layer by ultracentrifugation, which physically separates intact nuclei from lighter membrane and cytoplasmic contaminants[reference:34]. This is the step that generic "rapid nuclei lysis" kits lack — and the step that determines whether your snRNA-seq MtRatio is 5% or 28%.

2. >95% Nuclear Enrichment

The manufacturer reports >95% nuclear enrichment[reference:35] — the purity threshold required for single-nucleus genomics, where even minor cytoplasmic carryover inflates mitochondrial reads and background.

3. Designed for Solid Tissues and Fragile Nuclei

Unlike KTP4001 (optimized for cultured cells and homogenate tissues), KTP4002 is specifically designed for pure nuclei and fragile nuclei from mammalian cultured cells and solid tissues[reference:36]. The sucrose cushion protects fragile nuclei from mechanical shear during isolation.

4. Exceptional Cost-Effectiveness

At 2.45 per sample), KTP4002 is priced for routine use in single-nucleus genomics pipelines — not just occasional "special" samples[reference:37].

5. Frozen Nuclei Storage

Isolated nuclei can be preserved frozen for several months in the included Nuclei Storage Buffer[reference:38], enabling batch processing and reducing batch effects across time-course or multi-group designs.

6. Published Validation

Cited in 2 publications, including a LC-MS/MS method for quantifying Schisandrin B and exploring its intracellular exposure (Journal of Analytical Methods in Chemistry, IF 3)[reference:39].

Disadvantages

1. Requires Ultracentrifugation

The sucrose cushion workflow requires an ultracentrifuge capable of the specified g-force. Labs without ultracentrifuge access should use KTP4001 instead.

2. Longer Workflow Than KTP4001

The sucrose cushion adds a ultracentrifugation step compared to the rapid KTP4001 protocol. For applications where >95% purity is not required (e.g., routine nuclear protein Western blot), KTP4001 is faster.

3. Research Use Only

Not intended for human or clinical diagnosis.

Who Should Buy This Kit?

✅ Buy KTP4002 if you:

• Prepare nuclei for 10x snRNA-seq or snATAC-seq and need to keep MtRatio low
• Work with solid tissues (adipose, brain, tumor) where cytoplasmic contamination is severe
• Need >95% nuclear enrichment for chromatin accessibility or nuclear RNA assays
• Have struggled with fragile nuclei that lyse during rapid isolation protocols
• Want frozen nuclei storage for batch processing across time points
• Value a cost-effective kit ($2.45/sample) for routine single-nucleus genomics

❌ Consider alternatives if you:

• Do not have ultracentrifuge access — KTP4001 provides a rapid, centrifugation-based nuclei isolation without the sucrose cushion
• Only need nuclei for routine Western blot of nuclear proteins — KTP4001 is sufficient and faster

Quick Specs Summary

📌 Reference Link: ExKine™ Nuclei Extraction Kit (High Purity) — KTP4002