December 2022 News

      We release two new protein constructs, PROT-r-NF-L-Rct and PROT-r-NF-L-Stan. These constructs are designed to be used as protein standards for current neurofilament NF-L antibody based assays, such as the Uman/Quanterix NF-LIGHT™ and Quanterix Simoa™ assays. The two antibodies used in these assays both bind to the center of the “Coil II” region of α-helical “Rod” region of the NF-L molecule. The PROT-r-NF-L-Rct contains contains the entire Coil II region. The PROT-r-NF-L-Stan constructs contains the epitopes for both antibodies with little flanking sequence and is engineered to include 2 tryptophan residues. The result is a convenient low molecular weight protein standard which due to the high tryptophan content can be quantified spectrophotometrically more accurately than native or recombinant NF-L. Details of the mapping of the relevant NF-L assay antibodies and our generation of a novel panel of similar products are described in a recent BioRχiv publication, 10.1101/2022.08.27.504533v1.
      We hired an excellent immunohistochemist to the great dismay of the University of Florida so we will be validating all our antibodies on formalin fixed paraffin embedded sections, in other words for immunohistochemistry (IHC). The harsh fixation and processing typically used with IHC heavily modifies immunogens and it is therefore expected to cause some otherwise useful antibodies to not work well. However certain other antibodies may recognize epitopes which are not damaged by IHC and so should work just fine. So we added to the “Additional Info” tag of the relevant product web pages images and details of positive IHC results. We now present data on many of our chicken antibodies; Specifically MAP-τ CPCA-Tau, neurofilament NF-H CPCA-NF-H, neurofilament NF-L CPCA-NF-L, tyrosine hydroxylase CPCA-TH, FOX3/NeuN CPCA-FOX3, FOX2 CPCA-FOX2, mCherry CPCA-mCherry, GFP CPCA-GFP, GFAP CPCA-GFAP, IBA1 CPCA-IBA1, MAP2A/B CPCA-MAP2, calbindin CPCA-Calb, myelin basic protein CPCA-MBP, CNPase CPCA-CNP, secretogogin CPCA-SCGN, α-synuclein CPCA-SNCA and visinin-like protein 1 CPCA-VLP1. We have also validated several goat antibodies for formalin fixed paraffin embedded IHC including our antibody to CNPase GPCA-CNP, FOX3/NeuN GPCA-FOX3, GFAP GPCA-GFAP, GFP GPCA-gfP,
MAP2 GPCA-MAP2, MBP GPCA-MBP, mCherry GPCA-mCherry, NF-H GPCA-NF-H and tyrosine hydroxylase GPCA-TH. We have also validated some of our mouse monoclonal antibodies on paraffin embedded IHC, such as DegenoTag™ NF-L antibody MCA-1B11, antibody to mCherry MCA-1C51,
      Over the next few weeks we will validate all of our other chicken, mouse, rabbit and goat antibodies for IHC on human and rodent tissues, significantly enhancing their utility. We have already validated certain of our most widely used monoclonal antibodies such as MCA-1B7 which binds to FOX3/NeuN, an excellent marker of neurons, our rabbit polyclonal antibody to IBA1, RPCA-IBA1 an excellent marker of microglia and our monoclonal antibody to ubiquitin MCA-UBI-1, an excellent marker of Alzheimer neurofibrillary tangles and other pathological inclusions.
      We usually go to the normally annual Society for Neuroscience Meeting, but missed 2020 and 2021 due to the pandemic. This year the meeting was in San Diego, November 11-16, and it was fun to see various people for the first time in three years. We were at booth 401 and handed out ~1,000 of our well known poster images for free, and they had all gone by the middle of the second day. We took along a few of our slides of brain sections and HeLa cell stained with various of antibodies giving 5 distinctly different fluorescence signals at 405nm, 488nm, 541nm, 645nm and 750nm. So on the brain sections it is possible to visualize on one section some combination of nuclei, neuronal cell bodies, neuronal dendrites, myelin sheaths, axons, astrocytes and microglia. In the HeLa cells you could see some combination of nucleus, mitochondria, microfilaments, intermediate filaments, microtubules, plasma membrane, nucleoli and nuclear lamina. It turned out that the various microscope companies loved these, as they had apparently all been looking for such samples to demonstrate how their various 2 photon, confocal, fluorescence etc. microscopes worked. So we are starting to market these as a new line of products. For no particular reason Dr. Shaw also brought along some Ramon-Y-Cajal images which he had burned into wood using a laser and tastefully framed. These turned out to be very popular also, and we sold all of them. So there is yet another potential line of products, watch this space!

Recombinant Human NF-L Rod 80-400

Human NF-L sequence was based on that was NP_006149.2 which was inserted into the eukaryotic expression vector pET30a(+) which adds an N terminal His-tag and some other sequence, underlined below. This sequence includes a thrombin cleavage site (blue), an S-tag affinity peptide (red) and an enterokinase cleavage site (green). This construct is designed to express the entire α-helical “rod” region without the globular “head” or “tail” regions.


MHHHHHHSSG LVPRGSGMKE TAAAKFERQH MDSPDLGTDD DDKAMADIGS EFTQEKAQLQ  60
DLNDRFASFI ERVHELEQQN KVLEAELLVL RQKHSEPSRF RALYEQEIRD LRLAAEDATN 120
EKQALQGERE GLEETLRNLQ ARYEEEVLSR EDAEGRLMEA RKGADEAALA RAELEKRIDS 180
LMDEISFLKK VHEEEIAELQ AQIQYAQISV EMDVTKPDLS AALKDIRAQY EKLAAKNMQN 240
AEEWFKSRFT VLTESAAKNT DAVRAAKDEV SESRRLLKAK TLEIEACRGM NEALEKQLQE 300
LEDKQNADIS AMQDTINKLE NELRTTKSEM ARYLKEYQDL LNVKMALDIE IAAYRKLLEG 360
EETRL 365

Number of amino acids: 365
Molecular weight: 41898.93
Theoretical pI: 4.97

Amino acid composition:
Ala (A) 44 12.1%
Arg (R) 27 7.4%
Asn (N) 12 3.3%
Asp (D) 25 6.8%
Cys (C) 1 0.3%
Gln (Q) 22 6.0%
Glu (E) 53 14.5%
Gly (G) 11 3.0%
His (H) 10 2.7%
Ile (I) 14 3.8%
Leu (L) 42 11.5%
Lys (K) 27 7.4%
Met (M) 12 3.3%
Phe (F) 8 2.2%
Pro (P) 4 1.1%
Ser (S) 19 5.2%
Thr (T) 14 3.8%
Trp (W) 1 0.3%
Tyr (Y) 7 1.9%
Val (V) 12 3.3%

Total number of negatively charged residues (Asp + Glu): 78
Total number of positively charged residues (Arg + Lys): 54

Extinction coefficients are in units of M-1 cm-1, at 280 nm measured in water.

Ext. coefficient 15930
Abs 0.1% (=1 g/l) 0.380, assuming all pairs of Cys residues form cystines

Ext. coefficient 15930
Abs 0.1% (=1 g/l) 0.380, assuming all Cys residues are reduced

Recombinant Full Length Human NF-L

Human NF-L sequence was based on that was NP_006149.2 which was inserted into the eukaryotic expression vector pET30a(+) which adds an N terminal His-tag and some other sequence, underlined below. This sequence includes a thrombin cleavage site (blue), an S-tag affinity peptide (red) and an enterokinase cleavage site (green).


MHHHHHHSSG LVPRGSGMKE TAAAKFERQH MDSPDLGTDD DDKAMADIGS EFMSSFSYEP  60
YYSTSYKRRY VETPRVHISS VRSGYSTARS AYSSYSAPVS SSLSVRRSYS SSSGSLMPSL 120
ENLDLSQVAA ISNDLKSIRT QEKAQLQDLN DRFASFIERV HELEQQNKVL EAELLVLRQK 180
HSEPSRFRAL YEQEIRDLRL AAEDATNEKQ ALQGEREGLE ETLRNLQARY EEEVLSREDA 240
EGRLMEARKG ADEAALARAE LEKRIDSLMD EISFLKKVHE EEIAELQAQI QYAQISVEMD 300
VTKPDLSAAL KDIRAQYEKL AAKNMQNAEE WFKSRFTVLT ESAAKNTDAV RAAKDEVSES 360
RRLLKAKTLE IEACRGMNEA LEKQLQELED KQNADISAMQ DTINKLENEL RTTKSEMARY 420
LKEYQDLLNV KMALDIEIAA YRKLLEGEET RLSFTSVGSI TSGYSQSSQV FGRSAYGGLQ 480
TSSYLMSTRS FPSYYTSHVQ EEQIEVEETI EAAKAEEAKD EPPSEGEAEE EEKDKEEAEE 540
EEAAEEEEAA KEESEEAKEE EEGGEGEEGE ETKEAEEEEK KVEGAGEEQA AKKKD 595


Number of amino acids: 595

Molecular weight: 67224.80
Theoretical pI: 4.69

Amino acid composition:
Ala (A) 65 10.9%
Arg (R) 37 6.2%
Asn (N) 14 2.4%
Asp (D) 30 5.0%
Cys (C) 1 0.2%
Gln (Q) 29 4.9%
Glu (E) 102 17.1%
Gly (G) 25 4.2%
His (H) 12 2.0%
Ile (I) 20 3.4%
Leu (L) 50 8.4%
Lys (K) 41 6.9%
Met (M) 15 2.5%
Phe (F) 12 2.0%
Pro (P) 11 1.8%
Ser (S) 62 10.4%
Thr (T) 24 4.0%
Trp (W) 1 0.2%
Tyr (Y) 21 3.5%
Val (V) 23 3.9%
Total number of negatively charged residues (Asp + Glu): 132
Total number of positively charged residues (Arg + Lys): 78

Extinction coefficients are in units of M-1 cm-1, at 280 nm measured in water.

Ext. coefficient 36790
Abs 0.1% (=1 g/l) 0.547, assuming all pairs of Cys residues form cystines

Ext. coefficient 36790
Abs 0.1% (=1 g/l) 0.547, assuming all Cys residues are reduced

Recombinant Human NF-L Coil II 256-400

Human NF-L sequence was based on that in NP_006149.2 which was inserted into the eukaryotic expression vector pET30a(+) which adds an N terminal His-tag and some other sequence, underlined below. This sequence includes a thrombin cleavage site (blue), an S-tag affinity peptide (red) and an enterokinase cleavage site (green). This construct expresses the entire α-helical Coil II region, which includes the epitopes for the mouse monoclonal antibodies utilized in the Uman-NF-Light™, the NF-L Simoa™ assay and others. This construct is therefore an excellent standard for these assays.


MHHHHHHSSG LVPRGSGMKE TAAAKFERQH MDSPDLGTDD DDKAMADIGS EFAALKDIRA  60
QYEKLAAKNM QNAEEWFKSR FTVLTESAAK NTDAVRAAKD EVSESRRLLK AKTLEIEACR 120
GMNEALEKQL QELEDKQNAD ISAMQDTINK LENELRTTKS EMARYLKEYQ DLLNVKMALD 180
IEIAAYRKLL EGEETRL 197

Number of amino acids: 197

Molecular weight: 22,395.19 Da

Theoretical pI: 5.46

Amino acid composition:
Ala (A) 25 12.7%
Arg (R) 12 6.1%
Asn (N) 8 4.1%
Asp (D) 15 7.6%
Cys (C) 1 0.5%
Gln (Q) 8 4.1%
Glu (E) 23 11.7%
Gly (G) 7 3.6%
His (H) 7 3.6%
Ile (I) 7 3.6%
Leu (L) 20 10.2%
Lys (K) 18 9.1%
Met (M) 9 4.6%
Phe (F) 4 2.0%
Pro (P) 2 1.0%
Ser (S) 11 5.6%
Thr (T) 10 5.1%
Trp (W) 1 0.5%
Tyr (Y) 4 2.0%
Val (V) 5 2.5%

Total number of negatively charged residues (Asp + Glu): 38
Total number of positively charged residues (Arg + Lys): 30

Extinction coefficients:

Ext. coefficient 11460
Abs 0.1% (=1 g/l) 0.512, assuming all pairs of Cys residues form cystines

Ext. coefficient 11460
Abs 0.1% (=1 g/l) 0.512, assuming all Cys residues are reduced

April 2021 News

      We publish another collaboration between scientists at the University of Florida and EnCor, “TNF increases tyrosine hydroxylase expression in human monocytes” by Madison et al., BioRΧiv 10.1101/2021.04.13.439627v1, It describes in detail an ELISA developed using EnCor antibodies which can be used for quantitation of tyrosine hydroxylase (TH) levels in a variety of experimental and clinical contexts. The specific antibodies used are our mouse monoclonal antibody MCA-4H2 and our rabbit polyclonal RPCA-TH. They also used our chicken polyclonal to the cell division marker Ki67 CPCA-Ki67. Previously the same group showed that TH levels were detectable in blood cells of healthy control and Parkinson’s patients and that the levels detected in Parkinson’s patients were significantly higher, a potential very significant finding.
      We have been very interested in recent studies of NF-L, neurofilament light, as a biomarker of neuronal damage and degeneration. Much of the recent work has been performed with the excellent Uman NF-Light Assay. The epitopes recognized by the two antibodies used in this assay are not known, and so we have been working to fully characterize them. As part of this work we generated a codon optimized cDNA designed to express amino acids 256-400 of the α-helical rod region of human neurofilament NF-L, specifically the Coil 2a and Coil 2b regions. Our full length recombinant human NF-L protein Prot-r-NF-L is widely used as a protein standard in ELISA, Simoa and other kinds of antibody based assays for NF-L detection, including the Uman assay. Our new truncated product, Prot-r-NF-L-rct, contains the epitopes for both the capture and detect NF-L monoclonal antibodies used in the Uman NF-Light assay and also the epitope for our mouse NF-L monoclonal MCA-1B11. This product may therefore be a more convenient protein standard for use with the Uman and similar NF-L assays, and our new data suggests that MCA-1B11 may form the basis of further NF-L assays.
      We also updated our product data for several of our recombinant proteins including mCherry Prot-r-mCherry and GFP Prot-r-acGFP.