Hematoxylin (Natural Black 1), a naturally occurring flavonoid compound derived from the logwood tree, Haematoxylon campechianum. Hematoxylin is a nuclear stain in histology and is also a potent Aβ42 fibrillogenesis inhibitor with an IC₅₀ of 1.6 µM.

IC50: 1.6 µM (Aβ42 fibrillogenesis)^[2]

When exposed to air, Hematoxylin is oxidized to reddish brown hematein. When oxidized to its hematein form and combined with a mordant, usually a metal salt, Hematoxylin stains tissue sections a deep blue to black color depending on the staining method. By itself, Hematoxylin is also amphoteric in its hematein form; it is red at acid pH and blue at alkaline pH. Differentiation following Hematoxylin staining removes nonspecific staining^[1].
Hematoxylin treatment greatly alleviates Aβ42-induced cytotoxicity in SH-SY5Y cells. Hematoxylin is a potential agent against Aβ fibrillogenesis and cytotoxicity^[2].
The Hematoxylin and Eosin (HE) stained tissue section is the cornerstone of anatomical pathology diagnosis. The HE procedure stains the nucleus and cytoplasm contrasting colors to readily differentiate cellular components^[3].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Guidelines (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs).
The method of HE staining^[4]:
1. Place the glass slides that hold the paraffin sections in staining racks. Clear the paraffin from the samples in three changes of xylene for 2 min per change.
2. Hydrate the samples as follows.
i. Transfer the slides through three changes of 100% ethanol for 2 min per change.
ii. Transfer to 95% ethanol for 2 min.
iii. Transfer to 70% ethanol for 2 min.
iv. Rinse the slides in running tap water at room temperature for at least 2 min.
3. Stain the samples in Hematoxylin solution for 3 min.
4. Place the slides under running tap water at room temperature for at least 5 min.
5. Stain the samples in working eosin Y solution for 2 min.
6. Dehydrate the samples as follows.
i. Dip the slides in 95% ethanol about 20 times.
ii. Transfer to 95% ethanol for 2 min.
iii. Transfer through two changes of 100% ethanol for 2 min per change.
7. Clear the samples in three changes of xylene for 2 min per change.
8. Place a drop of Permount over the tissue on each slide and add a coverslip. View the slides using a microscope.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

302.28

C₁₆H₁₄O₆

517-28-2

苏木精；苏木色精；苏木素

Room temperature in continental US; may vary elsewhere.

DMSO : 50 mg/mL (165.41 mM; Need ultrasonic)

H₂O : 6.67 mg/mL (22.07 mM; Need ultrasonic)

请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。
储备液的保存方式和期限：-80°C, 6 months; -20°C, 1 month。-80°C 储存时，请在 6 个月内使用，-20°C 储存时，请在 1 个月内使用。

请根据您的实验动物和给药方式选择适当的溶解方案。以下溶解方案都请先按照 In Vitro 方式配制澄清的储备液，再依次添加助溶剂：

——为保证实验结果的可靠性，澄清的储备液可以根据储存条件，适当保存；体内实验的工作液，建议您现用现配，当天使用； 以下溶剂前显示的百
分比是指该溶剂在您配制终溶液中的体积占比；如在配制过程中出现沉淀、析出现象，可以通过加热和/或超声的方式助溶

• 1.

  请依序添加每种溶剂：;10% DMSO ;; 40% PEG300 ;; 5% Tween-80 ;; 45% saline

  Solubility: ≥ 2.5 mg/mL (8.27 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (8.27 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀；向上述体系中加入50 μL Tween-80，混合均匀；然后继续加入 450 μL生理盐水定容至 1 mL。

  将 0.9 g 氯化钠，完全溶解于 100 mL ddH₂O 中，得到澄清透明的生理盐水溶液

• 2.

  请依序添加每种溶剂：;10% DMSO ;; 90% (20% SBE-β-CD in saline)

  Solubility: ≥ 2.5 mg/mL (8.27 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (8.27 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL 20% 的 SBE-β-CD 生理盐水水溶液中，混合均匀。

  将 2 g 磺丁基醚 β-环糊精加入 5 mL 生理盐水中，再用生理盐水定容至 10 mL，完全溶解，澄清透明
• 3.

  请依序添加每种溶剂：;10% DMSO ;; 90% corn oil

  Solubility: ≥ 2.5 mg/mL (8.27 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (8.27 mM，饱和度未知) 的澄清溶液，此方案不适用于实验周期在半个月以上的实验。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. M Titford. The long history of hematoxylin. Biotech Histochem. Mar-Apr 2005;80(2):73-8.

  [2]. Yilong Tu, et al. Hematoxylin Inhibits Amyloid β-Protein Fibrillation and Alleviates Amyloid-Induced Cytotoxicity. J Phys Chem B. 2016 Nov 10;120(44):11360-11368.

  [3]. Ada T Feldman, et al. Tissue processing and hematoxylin and eosin staining. Methods Mol Biol. 2014;1180:31-43.

  [4]. Robert D Cardiff, et al. Manual hematoxylin and eosin staining of mouse tissue sections. Cold Spring Harb Protoc. 2014 Jun 2;2014(6):655-8.