Sandwich ELISA, HRP-labelled antibody
Urine, Bronchoalveolar lavage, Milk, Seminal plasma, Plasma (EDTA, citrate, heparin)
Plasma: 35 µl/well
Urine: 20 µl/well
Breast milk, BALF, Seminal plasma: 5 µl/well
At ambient temperature. Upon receipt, store the product at the temperature recommended below.
Store the complete kit at 2–8°C. Under these conditions, the kit is stable until the expiration date (see label on the box)
Limit of Detection
n = 8; CV = 3.8 %
n = 6; CV = 12.2 %
Plasma (EDTA): 92.6 %
Plasma (EDTA): 105.7 %
Urine: 100.7 %
Breast milk: 109.4 %
Seminal plasma: 103.5 %
BALF: 115.4 %
- It is intended for research use only
- The total assay time is less than 3 hours
- The kit measures prolactin inducible protein in human plasma (EDTA, citrate, heparin), seminal plasma (SP), breast milk (BM), bronchoalveolar lavage fluid (BALF) and urine
- Assay format is 96 wells
- Standard is purified human native protein
- Components of the kit are provided ready to use, concentrated or lyophilized
Prolactin inducible protein (PIP) also known as gross cystic disease fluid protein 15 (GCDFP-15), extra-parotid glycoprotein (EP-GP), gp17 seminal actin-binding protein (SABP) or BRST2 is a 17-kDa single polypeptide chain that in humans is encoded by the PIP gene located on chromosome 7.
The PIP gene is expressed in most organs that contribute to human body fluids. It was first identified as a major component of breast cyst fluid, it is also present in human milk, saliva, amniotic fluid, seminal plasma, and particularly those with apocrine and exocrine organs. Due to posttranslational modification and different glycan content PIP exists in many isoforms with different molecular mass and isoelectric points. PIP may exist as a dimer or tetramer in different fluids. The protein forms dimers in saliva and tetramers in breast cyst fluid and human seminal fluid.
PIP is a secreted protein and it is upregulated by prolactin and androgens and downregulated by estrogen. PIP binds to many proteins such as fibrinogen, actin, keratin, myosin, tropomyosin and zinc a2-glycoprotein (ZAG). PIP has strong affinity for the Fc fragment of immunoglobulin G (IgG), and it could bind with antisperm antibody (ASA), which acts to protect spermatozoa from the damage by IgG. PIP also has high affinity for CD4-TCR (cluster of differentiation – T cell receptor), which modulates the immune response during the viral infection.
It was reported the isolation of native human serum albumin (HSA)–PIP complex from human seminal plasma. Albumin has been known to preserve the motility of sperm, thus the native HSA–PIP complex in human seminal plasma may suggest another important role of PIP, which can directly be correlated with male fertility/infertility. It was also shown that expression of PIP is down-regulated in azoospermia.
In a larger study, immunohistochemical analysis revealed expression of PIP in 72% of breast carcinoma samples. PIP protein expression was also used in the differential diagnosis of metastatic breast cancer versus other primary origin carcinomas. The presence of PIP protein in the serum of some breast cancer patients has been detected by Western blot analysis and circulating anti-PIP antibodies have been identified in sera of patients with both malignant and benign breast disease. PIP is also considered a prognostic biomarker for prostate carcinoma, although its role in prostate tumor progression is not yet fully established. The comparison
between PIP expression in normal prostate tissues and adenocarcinoma of the prostate showed that benign prostate epithelium expresses PIP at low levels, whereas, PIP is overexpressed in carcinomas of the prostate, indicating its role in tumor progression. Apart from breast and prostate cancers the overexpression of PIP has also been observed in other carcinomas (ovary, colon, renal cell carcinoma, pancreatic carcinoma)